Device-directed utterance detection

ABSTRACT

A speech interface device is configured to detect an interrupt event and process a voice command without detecting a wakeword. The device includes on-device interrupt architecture configured to detect when device-directed speech is present and send audio data to a remote system for speech processing. This architecture includes an interrupt detector that detects an interrupt event (e.g., device-directed speech) with low latency, enabling the device to quickly lower a volume of output audio and/or perform other actions in response to a potential voice command. In addition, the architecture includes a device directed classifier that processes an entire utterance and corresponding semantic information and detects device-directed speech with high accuracy. Using the device directed classifier, the device may reject the interrupt event and increase a volume of the output audio or may accept the interrupt event, causing the output audio to end and performing speech processing on the audio data.

BACKGROUND

Speech recognition systems have progressed to the point where humans caninteract with computing devices using their voices. Such systems employtechniques to identify the words spoken by a human user based on thevarious qualities of a received audio input. Speech recognition combinedwith natural language understanding processing techniques enablespeech-based user control of a computing device to perform tasks basedon the user's spoken commands. The combination of speech recognition andnatural language understanding processing techniques is referred toherein as speech processing. Speech processing may also involveconverting a user's speech into text data which may then be provided tovarious text-based software applications.

Speech processing may be used by computers, hand-held devices, telephonecomputer systems, kiosks, and a wide variety of other devices to improvehuman-computer interactions.

BRIEF DESCRIPTION OF DRAWINGS

For a more complete understanding of the present disclosure, referenceis now made to the following description taken in conjunction with theaccompanying drawings.

FIG. 1 illustrates a system configured to perform interrupt detectionaccording to embodiments of the present disclosure.

FIGS. 2A-2B are conceptual diagrams of components of a system accordingto embodiments of the present disclosure.

FIG. 3A is a conceptual diagram of how automatic speech recognition isperformed according to embodiments of the present disclosure.

FIG. 3B is a conceptual diagram of how natural language processing isperformed according to embodiments of the present disclosure.

FIG. 4 is a conceptual diagram of how natural language processing isperformed according to embodiments of the present disclosure.

FIG. 5A is a conceptual diagram of components of a system to detect ifinput audio data includes system directed speech according toembodiments of the present disclosure.

FIG. 5B is a conceptual diagram illustrating a system operating todetect if input audio data includes system directed speech according toembodiments of the present disclosure.

FIG. 6 illustrates data stored and associated with user profilesaccording to embodiments of the present disclosure.

FIGS. 7A-7C are signal flow diagrams illustrating the processingperformed when a remote system detects system-directed speechrepresented in input audio data and performs speech processing on theinput audio data according to embodiments of the present disclosure.

FIGS. 8A-8C are signal flow diagrams illustrating the processingperformed when a device detects system-directed speech represented ininput audio data and sends the input audio data to a remote system forspeech processing according to embodiments of the present disclosure.

FIGS. 9A-9B are signal flow diagrams illustrating the processingperformed when a device detects system-directed speech represented ininput audio data and performs local speech processing on the input audiodata according to embodiments of the present disclosure.

FIG. 10 illustrates an example of on-device interrupt architectureaccording to embodiments of the present disclosure.

FIG. 11 illustrates an example of wakewordless interrupt according toembodiments of the present disclosure.

FIGS. 12A-12D illustrate examples of different ways that the interruptarchitecture may process an utterance according to embodiments of thepresent disclosure.

FIG. 13 illustrates a decision table and training data associated withinterrupt architecture according to embodiments of the presentdisclosure.

FIG. 14 is a flowchart conceptually illustrating an example method forperforming interrupt processing according to embodiments of the presentdisclosure.

FIG. 15 is a flowchart conceptually illustrating an example method fortraining an interrupt detector according to embodiments of the presentdisclosure.

FIG. 16 illustrates example implementations for interrupt architectureaccording to embodiments of the present disclosure.

FIG. 17 illustrate example implementations for wakewordless interruptarchitecture according to embodiments of the present disclosure.

FIG. 18 is a block diagram conceptually illustrating example componentsof a device according to embodiments of the present disclosure.

FIG. 19 is a block diagram conceptually illustrating example componentsof a server according to embodiments of the present disclosure.

FIG. 20 illustrates an example of a computer network for use with thespeech processing system.

DETAILED DESCRIPTION

Automatic speech recognition (ASR) is a field of computer science,artificial intelligence, and linguistics concerned with transformingaudio data associated with speech into text data representative of thatspeech. Natural language understanding (NLU) is a field of computerscience, artificial intelligence, and linguistics concerned withenabling computers to derive meaning from text input containing naturallanguage. Text-to-speech (TTS) is a field of computer science,artificial intelligence, and linguistics concerned with enablingcomputers to output synthesized speech. ASR, NLU, and TTS may be usedtogether as part of a speech processing system.

A speech processing computing system may be configured to answer usercommands requesting the output of content. For example, a user may say“what is the weather in Seattle.” The system may determine contentresponsive to the command (e.g., weather information for Seattle) andoutput the content to the user. The input of speech corresponding to acommand, the processing of the command to determine output content, andthe output of the content may be considered a “turn.”

Such a system may be configured to commence a turn when a user devicedetects speech corresponding to a wakeword (e.g., “Alexa”). A userdevice may remain in a wakeword detection mode until the device detectsspeech corresponding to the wakeword. While in wakeword detection mode,the device may continuously buffer, process, and, if the wakeword is notdetected, discard captured audio. Once the device detects the wakeword,however, the device may begin sending audio data for the captured audio(and/or buffered audio) to one or more server(s) for processing. Oncethe server(s) has enough audio data to process (for example, aspeech-endpoint has been reached in the audio data), the device maycease sending audio data to the server(s). The device may continuallyprocess captured audio to detect the wakeword, even while the device isoutputting content responsive to input speech.

A user may speak a wakeword along with an initial command. When thedevice detects the wakeword, the device sends audio data correspondingto the initial command to a remote system. The remote system maydetermine more information is needed from the user in order for theremote system to determine a response to the initial command. Forexample, the user may request the remote system add an item to a list,but may not say what the item is. In such instances, the remote systemmay cause the device to output synthesized speech or another form ofprompt soliciting the additional information from the user. In such asituation the remote system may also instruct the device to send furtheraudio data to the remote system (which may represent speech includingthe prompted-for information) without first determining if a wakewordwas spoken. Thus, if the user speaks the additional information inresponse to the prompt without first speaking the wakeword, theadditional speech may be captured by the device. The device may thensend audio data corresponding to the additional information to theserver(s) without first detecting a spoken wakeword. Such situations maybe referred to as dialog driven slot filling in which the user needs toprovide additional information in order for the system to output aresponse to the user corresponding to the ongoing dialog (e.g., theconversation) between the system and the user. Such operations may beperformed when the system determines that additional information isneeded from the user in order to complete an operation of a pendingcommand (e.g., processing related to a particular dialog is ongoing).

In certain situations, however, it may be desirable for a user (who hasgranted consent) to have a local device configured to capture audio andprocess (and possibly send) audio data to the remote system, even if noinformation is needed by the system to complete operation of a pendingcommand/dialog and the audio data does not include a representation ofthe wakeword. For example, after completing a response to an utterance(or group of utterances as part of a dialog), the local device maycontinue to process audio data (e.g., for some user-approved amount oftime) to detect device-directed speech and, if detected, send the audiodata for speech processing (e.g., locally and/or remotely), includinginstances (with user consent) when the wakeword was not detected.

Thus, the present disclosure improves speech processing and otheraudio-based user interface systems by enabling a user device to detectdevice-directed speech and send audio data representing thedevice-directed speech for processing (e.g., even when the particularaudio data to be processed may not include a representation of a spokenwakeword, for example when one utterance includes the wakeword but afollow-up utterance does not). The local device may detect thedevice-directed speech while operations related to a previousutterance/dialog are ongoing and/or have concluded. For example, whilethe local device is generating output audio corresponding to theprevious utterance, the local device may detect device-directed speechand perform first action(s), such as pausing the output audio, reducinga volume level of the output audio, displaying indicator light(s),sending audio data to the remote system, and/or the like.

The local device may include on-device interrupt architecture configuredto detect when the device-directed speech is present. This architecturemay include an interrupt detector that detects an interrupt event (e.g.,device-directed speech) with low latency, enabling the local device toquickly lower a volume level of the output audio and/or perform otheractions in response to a potential voice command. In addition, thearchitecture includes a device directed classifier that processes anentire utterance and corresponding semantic information in order todetect device-directed speech with high accuracy. Using the devicedirected classifier, the local device may reject the interrupt event andincrease a volume level of the output audio or may accept the interruptevent, causing the output audio to end and the sending the audio data tothe remote system. The teachings of the present disclosure reducesystem/user friction, thereby providing a better user experience.

As illustrated in FIG. 1, disclosed is a system 100 for processingcommands in a distributed system according to embodiments of the presentdisclosure. Although the figures and discussion illustrate certainoperational steps of the system in a particular order, the stepsdescribed may be performed in a different order (as well as certainsteps removed or added) without departing from the intent of thedisclosure. A device 110 local to a user 5 and one or more server(s)included in remote system 120 may communicate across one or morenetwork(s) 199.

To detect user speech or other audio, the device 110 may use one or moremicrophones(s) 114 to generate input audio data that captures audio in aroom (e.g., an environment) in which the device 110 is located. Forexample, if the device 110 are located within earshot of a user 5, thedevice 110 may capture audio data representing speech generated by theuser 5. As is known and as used herein, “capturing” an audio signalincludes a microphone transducing audio waves (e.g., sound waves) ofcaptured sound to an electrical signal and a codec digitizing the signalto generate the microphone audio data.

The device 110 may process voice commands received from the user 5,enabling the user 5 to control the devices 110 and/or other devicesassociated with a user profile corresponding to the user 5. For example,the device 110 may include a wakeword engine (e.g., wakeword detector)that processes first input audio data to detect a representation of awakeword. When a wakeword is detected in the first input audio data, thedevice 110 may generate second input audio data corresponding to thewakeword and send the second input audio data to the remote system 120for speech processing. The remote system 120 may process the secondinput audio data, determine the voice command, and perform one or moreactions based on the voice command. For example, the remote system 120may generate a command instructing the device 110 (or any other device)to perform an action, may generate output audio data corresponding tothe action, may send response data (including the output audio dataand/or the command) to the device 110, and the device 110 may perform anaction.

In some examples, the remote system 120 may generate playback audio dataand send the playback audio data to the device 110. For example, theplayback audio data may be the output audio data corresponding to theaction described above, such as a notification generated usingtext-to-speech (TTS) process. However, the disclosure is not limitedthereto and in some examples the playback audio data may correspond tomusic or other audio data associated with the voice command withoutdeparting from the disclosure. Additionally or alternatively, the device110 may generate the playback audio data without departing from thedisclosure.

As illustrated in FIG. 1, the device 110 may receive (130) the playbackaudio data and may generate (132) output audio using the playback audiodata. For example, the device 110 may send the playback audio data tothe loudspeaker(s) 116 to generate the output audio.

The device 110 may generate (134) input audio data using themicrophone(s) 114, may determine (136) that an interrupt event isdetected in the input audio data, and may modify (138) output of theoutput audio. For example, the device 110 may pause the output audio,reduce a volume level of the output audio (e.g., from a first volumelevel to a second volume level), and/or perform other actions (e.g.,display visual indicator(s)). The device 110 may detect the interruptevent using an interrupt detector 1010, which is described in greaterdetail below with regard to FIG. 10. The interrupt detector 1010 isconfigured to detect the interrupt event with low latency (e.g.,processing a shorter duration of time and/or smaller quantity of audiodata), enabling the device 110 to be responsive to a potential voicecommand from the user 5.

The device 110 may determine (140) whether device-directed speech (e.g.,system-directed speech, device-directed speech event) is detected in theinput audio data. As will be described in greater detail below withregard to FIG. 10, the device 110 may determine whether device-directedspeech is detected using at least one classifier. For example, theclassifier may consider a variety of information, including a volumelevel of the speech (e.g., whether the speech is louder or quieter thannormal speech), speaker identification (e.g., identification data)corresponding to the speech, which may be determined using voicerecognition, image data, and/or other techniques known to one of skillin the art, emotion detection (e.g., emotion data) corresponding to thespeech (e.g., whether the speech is animated or quiet, for example), alength of time between when the output audio begins and when the speechis detected, and/or the like without departing from the disclosure.

If a device-directed speech event is not detected, the device 110 maycontinue (144) generating output audio (e.g., un-pause the output audio,increase a volume level of the output audio, and/or perform otheractions) and may perform (146) action(s) to stop indicating that thedevice 110 is listening. For example, the device 110 may stop displayingindicator lights or perform other actions to continue outputting audioas normal.

If a device-directed speech event is detected, however, the device 110may stop (148) generating the output audio (e.g., cause the output audioto stop), and may cause (150) speech processing to be performed on theinput audio data. For example, the device 110 may send the input audiodata to the remote system 120 for speech processing. Additionally oralternatively, the device 110 may perform local speech processing on theinput audio data without departing from the disclosure.

The device 110 may detect the device-directed speech event using adevice directed classifier 1020, which is described in greater detailbelow with regard to FIG. 10. Whereas the interrupt detector 1010 isconfigured to detect the interrupt event with low latency (e.g.,processes only a short duration/quantity of the input audio data), thedevice directed classifier 1020 is configured to detect thedevice-directed speech event with high accuracy and processes a greaterquantity of the utterance along with additional contextual and/orsemantic information. As described below with regard to FIG. 10,on-device interrupt architecture 1000 (e.g., barge-in detector) mayinclude the interrupt detector 1010 and the device directed classifier1020. The on-device interrupt architecture 1000 may detect adevice-directed speech event (e.g., system-directed speech event), whichmay be referred to as a barge-in event, and may cause speech processingto be performed on audio data corresponding to the device-directedspeech event.

As illustrated in steps 144-146, in some examples the device directedclassifier 1020 may determine that the device-directed speech event isnot present and may reject the interrupt event detected by the interruptdetector 1010. For example, the device 110 may detect speech but maydetermine that the speech does not correspond to a voice command. Whenthis occurs, the device 110 may continue generating the output audio atthe first volume level and may ignore the utterance. Additionally oralternatively, the device 110 may generate training data correspondingto the rejected interrupt event and may improve the interrupt detector1010 (e.g., classifier, trained model, etc. included in the interruptdetector 1010) using the training data. Thus, the device 110 may use thedevice directed classifier 1020 to improve the interrupt detector 1010without departing from the disclosure.

An audio signal is a representation of sound and an electronicrepresentation of an audio signal may be referred to as audio data,which may be analog and/or digital without departing from thedisclosure. For ease of illustration, the disclosure may refer to eitheraudio data or audio signals without departing from the disclosure.Additionally or alternatively, portions of a signal may be referenced asa portion of the signal or as a separate signal and/or portions of audiodata may be referenced as a portion of the audio data or as separateaudio data. For example, a first audio signal may correspond to a firstperiod of time (e.g., time range, such as 30 seconds) and a portion ofthe first audio signal corresponding to a second period of time (e.g., 1second) may be referred to as a first portion of the first audio signalor as a second audio signal without departing from the disclosure.Similarly, first audio data may correspond to the first period of time(e.g., 30 seconds) and a portion of the first audio data correspondingto the second period of time (e.g., 1 second) may be referred to as afirst portion of the first audio data or second audio data withoutdeparting from the disclosure. Audio signals and audio data may be usedinterchangeably, as well; a first audio signal may correspond to thefirst period of time (e.g., 30 seconds) and a portion of the first audiosignal corresponding to a second period of time (e.g., 1 second) may bereferred to as first audio data without departing from the disclosure.

As used herein, audio signals or audio data may correspond to a specificrange of frequency bands. For example, the audio data may correspond toa human hearing range (e.g., 20 Hz-20 kHz), although the disclosure isnot limited thereto.

The device 110 may use various techniques to determine whether audiodata includes speech and/or device-directed speech (e.g.,system-directed speech). Some embodiments may apply voice activitydetection (VAD) techniques. Such techniques may determine whether speechis present in audio data based on various quantitative aspects of theaudio data, such as the spectral slope between one or more frames of theaudio data; the energy levels of the audio data in one or more spectralbands; the signal-to-noise ratios of the audio data in one or morespectral bands; or other quantitative aspects. In other examples, thedevice 110 may implement a limited classifier configured to distinguishspeech from background noise. The classifier may be implemented bytechniques such as linear classifiers, support vector machines, anddecision trees. In still other examples, Hidden Markov Model (HMM) orGaussian Mixture Model (GMM) techniques may be applied to compare theaudio data to one or more acoustic models in storage, which acousticmodels may include models corresponding to speech, noise (e.g.,environmental noise or background noise), or silence. Still othertechniques may be used to determine whether speech is present in audiodata.

In some examples, the device 110 may include a voice activity detector(VAD) that may determine whether voice activity (e.g., speech) isdetected. For example, the VAD may use an instant loudness value of acurrent audio frame to track an upper envelope value (e.g., amplitude ofthe audio signal) and a lower envelope value (e.g., noise floor) and maydetermine whether voice activity is present by comparing the upperenvelope value to the noise floor. Thus, when the upper envelope valueis greater than the noise floor by more than a threshold value, the VADmay determine that voice activity is detected in the current audioframe. However, the disclosure is not limited thereto and the VAD mayperform voice activity detection using any techniques known to one ofskill in the art without departing from the disclosure.

As used herein, the loudness value may correspond to an amplitude, anaverage amplitude for a duration of time, and/or the like. For example,the loudness value can be a simple measurement of average power, such asa root mean square (RMS) value that is defined as a square root of meansquare (e.g., arithmetic mean of squares of a set of numbers), which mayalso be referred to as a quadratic mean. For ease of illustration, thedisclosure will refer to the loudness values as being RMS values,although the disclosure is not limited thereto.

As used herein, an instant loudness value corresponds to a single audioframe. In contrast, the VAD may track loudness values for a duration oftime, such that the upper envelope value and the lower envelope valuemay correspond to several audio frames. However, the disclosure is notlimited thereto and the upper envelope value and/or the lower envelopevalue may correspond to a single audio frame without departing from thedisclosure. In some examples, the VAD may determine the lower envelopevalue (e.g., noise floor) over a series of audio frames but determinethe upper envelope value based only on the instant loudness value of thecurrent audio frame, such that the VAD compares the instant loudnessvalue to the noise floor to determine whether voice activity is detectedin the current audio frame.

To illustrate a detailed example of performing voice activity detection,the VAD may track the upper envelope value using a first single-polefilter with asymmetric attack (e.g., very fast) and release (e.g., veryslow) speeds. Thus, the first single-pole filter will increase quicklywhen the instant loudness value is higher than the current upperenvelope value, but release slowly when the instant loudness value islower than the current upper envelope value, tracking the upper envelopeof the audio waveform despite fluctuations in the instant loudness valueover time. The first single-pole filter may switch to a faster releasespeed when the instant loudness value is consistently lower than theupper envelope value for a duration of time that exceeds a first timethreshold value. Thus, when the upper envelope value is consistentlyhigher than the instant loudness value, the first single-pole filterswitches to the faster release speed to accurately track the upperenvelope of the audio waveform.

Similarly, the VAD may track the lower envelope value (e.g., noisefloor) using a second single-pole filter with asymmetric attack (e.g.,very slow) and release (e.g., very fast) speeds. Thus, the secondsingle-pole filter will decrease quickly when the instant loudness valueis lower than the current lower envelope value, but increase slowly whenthe instant loudness value is higher than the current lower envelopevalue, tracking the lower envelope of the audio waveform despitefluctuations in the instant loudness value over time. The secondsingle-pole filter may switch to a faster attack speed when the instantloudness value is consistently higher than the lower envelope value fora duration of time that exceeds a second time threshold value. Thus,when the lower envelope value is consistently lower than the instantloudness value, the second single-pole filter switches to the fasterattack speed to accurately track the lower envelope of the audiowaveform. The second time threshold value may be equal to the first timethreshold value, although the disclosure is not limited thereto and thetime threshold values may vary without departing from the disclosure.

The second single-pole filter is able to track the level of stationarynoise (e.g., white noise or tonal) over time, enabling the VAD todetermine that an audio frame does not include voice activity (e.g.,VAD=0) even when the noise level is high. For example, the VAD maydetermine that voice activity is detected (e.g., VAD=1) when the upperenvelope value is greater than the lower envelope value by more than athreshold value. In some examples, the VAD may only determine that voiceactivity is detected when the upper envelope value is greater than thelower envelope value by more than the threshold value and the signallevel is higher than a minimum threshold value.

To improve the performance of the VAD, the device 110 may determine theloudness values (e.g., RMS values) using a logarithmic scale instead ofa linear scale. Thus, the loudness values (e.g., instant loudness value,upper envelope value, lower envelope value, etc.) may be measured indecibels (dB). However, the disclosure is not limited thereto and thedevice 110 may determine the loudness values using any techniques knownto one of skill in the art without departing from the disclosure.

In some examples, the VAD may perform smoothing (e.g., hangoversmoothing) when switching between VAD=0 and VAD=1 in order to fade thespeech/noise boundaries. For example, the VAD may perform smoothing for10 audio frames when initially detecting voice activity (e.g.,transitioning from VAD=0 to VAD=1). The VAD may not perform smoothingwhen switching between VAD=1 and VAD=0, although the disclosure is notlimited thereto.

Based on the VAD data generated by the VAD, the device 110 may classifyan audio frame as corresponding to speech (e.g., voice activity isdetected, represented as VAD=1) or non-speech (e.g., voice activity isnot detected, represented as VAD=0) and process the audio frameaccordingly. For ease of illustration, audio frames that are notassociated with voice activity (e.g., VAD=0) may be described asrepresenting non-speech, silence, and/or noise, whereas audio framesthat are associated with voice activity (e.g., VAD=1) may be describedas representing speech. However, the disclosure is not limited thereto.Depending on how the VAD is implemented, the VAD data may classify afirst audio frame that is below an energy threshold as non-speech,despite the first audio frame including a representation of speech,and/or may classify a second audio frame that is above the energythreshold as corresponding to speech, despite the second audio frame notincluding a representation of speech, without departing from thedisclosure.

As described in greater detail below with regard to FIG. 10, the device110 may include an interrupt detector 1010 configured to detect aninterrupt event by determining that input audio data representsdevice-directed speech. In some examples, the interrupt detector 1010may include a VAD to detect speech and a separate component configuredto determine that the speech is directed at the device 110 and/or theremote system 120. For example, the interrupt detector 1010 may includea classifier, trained model, and/or the like that receives input datafrom the VAD and/or other components and determines whetherdevice-directed speech is present. When the interrupt detector 1010determines that device-directed speech is present, the interruptdetector 1010 generates interrupt detector output indicating that aninterrupt event is detected. However, the disclosure is not limitedthereto and in other examples the interrupt detector 1010 may include asingle component that is configured to detect an interrupt event. Forexample, the interrupt detector 1010 may modify and/or train a VAD tonot only detect that speech is present but also determine that thespeech is directed at the device 110/remote system 120 without departingfrom the disclosure.

The trained model and other models described herein, which areimplemented by components of the system, may be trained and operatedaccording to various machine-learning techniques. Such techniques mayinclude, for example, neural networks (such as deep neural networks(DNNs) and/or recurrent neural networks (RNNs)), inference engines, andtrained classifiers. Examples of trained classifiers include SupportVector Machines (SVMs), neural networks, decision trees, adaptiveboosting (AdaBoost) combined with decision trees, and random forests.For example, SVM is a supervised learning model with associated learningalgorithms that analyze data and recognize patterns in the data, andwhich are commonly used for classification and regression analysis.Given a set of training examples, each marked as belonging to one of twocategories, an SVM training algorithm builds a model that assigns newexamples into one category or the other, making it a non-probabilisticbinary linear classifier. More complex SVM models may be built with thetraining set identifying more than two categories, with the SVMdetermining which category is most similar to input data. An SVM modelmay be mapped so that the examples of the separate categories aredivided by clear gaps. New examples are then mapped into that same spaceand predicted to belong to a category based on which side of the gapsthey fall on. Classifiers may issue a “score” indicating which categorythe data most closely matches. The score may provide an indication ofhow closely the data matches the category.

In order to apply machine learning techniques, machine learningprocesses themselves need to be trained. Training a machine learningcomponent requires establishing a “ground truth” for training examples.In machine learning, the term “ground truth” refers to the accuracy of atraining set's classification for supervised learning techniques.Various techniques may be used to train the models includingbackpropagation, statistical learning, supervised learning,semi-supervised learning, stochastic learning, or other knowntechniques.

In some embodiments, the trained model is a deep neural network (DNN)that is trained using distributed batch stochastic gradient descent;batches of training data may be distributed to computation nodes wherethey are fed through the DNN in order to compute a gradient for thatbatch. The device 110 may update the DNN by computing a gradient bycomparing audio data with a stored representation of a particular wordand back-propagating error data based thereon. In some embodiments, theDNN includes additional forward pass targets that estimate syntheticgradient values and the device 110 updates the DNN by selecting one ormore synthetic gradient values.

As described in greater detail below with regard to FIG. 13, the device110 may update and/or train the interrupt detector 1010 based ontraining data generated by the device directed classifier 1020. Forexample, the device 110 may generate the training data by treatingdevice directed classifier output generated by the device directedclassifier as a ground truth. Additionally or alternatively, the system100 may aggregate gradient(s) and/or training data from multiple devices110 to improve the interrupt detector 1010. For example, the system 100may use the gradient(s) and/or training data to train a first model andgenerate a second model and may then send the second model to the device110 to update the interrupt detector 1010, although the disclosure isnot limited thereto.

The system may operate using various components as described in FIG. 2.The various components may be located on same or different physicaldevices. Communication between various components may occur directly oracross a network(s) 199.

An audio capture component(s), such as a microphone or array ofmicrophones of the device 110, captures audio 11. The device 110processes audio data, representing the audio 11, to determine whetherspeech is detected. The device 110 may use various techniques todetermine whether audio data includes speech. Some embodiments may applyvoice activity detection (VAD) techniques. Such techniques may determinewhether speech is present in audio data based on various quantitativeaspects of the audio data, such as the spectral slope between one ormore frames of the audio data; the energy levels of the audio data inone or more spectral bands; the signal-to-noise ratios of the audio datain one or more spectral bands; or other quantitative aspects. In otherexamples, the device 110 may implement a limited classifier configuredto distinguish speech from background noise. The classifier may beimplemented by techniques such as linear classifiers, support vectormachines, and decision trees. In still other examples, Hidden MarkovModel (HMM) or Gaussian Mixture Model (GMM) techniques may be applied tocompare the audio data to one or more acoustic models in storage, whichacoustic models may include models corresponding to speech, noise (e.g.,environmental noise or background noise), or silence. Still othertechniques may be used to determine whether speech is present in audiodata.

Once speech is detected in audio data representing the audio 11, thedevice 110 may use a wakeword detection component 220 to performwakeword detection to determine when a user intends to speak an input tothe device 110. This process may also be referred to as wakeworddetection (e.g., keyword detection). An example wakeword is “Alexa.” Thedisclosure is not limited thereto, however, the device 110 may determinewhen a user intends to speak an input to the device 110 without usingthe wakeword detection component 220, as described in greater detailbelow.

Wakeword detection is typically performed without performing linguisticanalysis, textual analysis, or semantic analysis. Instead, the audiodata representing the audio 11 may be analyzed to determine if specificcharacteristics of the audio data match preconfigured acousticwaveforms, audio signatures, or other data to determine if the audiodata “matches” stored audio data corresponding to a wakeword. The storedaudio data may be provided by the remote system 120 and/or may beprovided by the user 5.

The wakeword detection component 220 may compare audio data to storedmodels or data to detect a wakeword. One approach for wakeword detectionapplies general large vocabulary continuous speech recognition (LVCSR)systems to decode audio signals, with wakeword searching being conductedin the resulting lattices or confusion networks. LVCSR decoding mayrequire relatively high computational resources. Another approach forwakeword spotting builds HMMs for each wakeword and non-wakeword speechsignals, respectively. The non-wakeword speech includes other spokenwords, background noise, etc. There can be one or more HMMs built tomodel the non-wakeword speech characteristics, which are named fillermodels. Viterbi decoding is used to search the best path in the decodinggraph, and the decoding output is further processed to make the decisionon wakeword presence. This approach can be extended to includediscriminative information by incorporating a hybrid DNN-HMM decodingframework. In another example, the wakeword detection component 220 maybe built on deep neural network (DNN)/recursive neural network (RNN)structures directly, without HMM being involved. Such an architecturemay estimate the posteriors of wakewords with context information,either by stacking frames within a context window for DNN, or using RNN.Follow-on posterior threshold tuning or smoothing is applied fordecision making. Other techniques for wakeword detection, such as thoseknown in the art, may also be used.

When the wakeword detection component 220 detects the wakeword, thedevice 110 may begin transmitting audio data 211, representing the audio11, to the remote system 120. The audio data 211 may include datacorresponding to the wakeword, or the portion of the audio data 211corresponding to the wakeword may be removed by the device 110 prior tosending the audio data 211 to the remote system 120. The disclosure isnot limited thereto, however, and in some examples the device 110 maydetect device-directed speech and/or system-directed speech instead ofthe wakeword without departing from the disclosure. When device-directedspeech and/or system-directed speech is detected, the device 110 maybegin transmitting audio data 211, representing the audio 11, to theremote system 120.

Upon receipt by the remote system 120, the audio data 211 may be sent toan orchestrator component 230. The orchestrator component 230 mayinclude memory and logic that enable the orchestrator component 230 totransmit various pieces and forms of data to various components of thesystem, as well as perform other operations.

The orchestrator component 230 sends the audio data 211 to a speechprocessing component 240. In some examples, the speech processingcomponent 240 may include an ASR component 250 and an NLU component 260that are configured to process the audio data 211 to generate NLU data.However, the disclosure is not limited thereto and in other examples,the speech processing component 240 may include a spoken languageunderstanding (SLU) component 255 that is configured to process theaudio data 211 to generate the NLU data. Additionally or alternatively,the speech processing component 240 may include the ASR component 250,the NLU component 260 and/or the SLU component 255 without departingfrom the disclosure.

An ASR component 250 of the speech processing component 240 transcribesthe audio data 211 into text data. The text data output by the ASRcomponent 250 represents one or more than one (e.g., in the form of anN-best list) hypotheses representing speech contained in the audio data211. The ASR component 250 interprets the speech in the audio data 211based on a similarity between the audio data 211 and pre-establishedlanguage models. For example, the ASR component 250 may compare theaudio data 211 with models for sounds (e.g., subword units, such asphonemes, etc.) and sequences of sounds to identify words that match thesequence of sounds of the speech represented in the audio data 211. TheASR component 250 sends (either directly or via the orchestratorcomponent 230) the text data generated thereby to an NLU component 260of the speech processing component 240. The text data sent from the ASRcomponent 250 to the NLU component 260 may include a top scoring ASRhypothesis or may include an N-best list including multiple ASRhypotheses. An N-best list may additionally include a respective scoreassociated with each ASR hypothesis represented therein. Each score mayindicate a confidence of ASR processing performed to generate the ASRhypothesis with which the score is associated.

The orchestrator component 230 (or other component) may also track adialog and dialog state across multiple utterances. A dialog is anexchange between the user and the system where the user speaks a commandand the system executes it. While many dialogs involve a singleutterance, many dialogs may involve many different utterances toultimately execute the action called for by the user. For example, ifthe user asks the system to order a pizza, the system may invoke a pizzaordering skill and may prompt the user several times for severalutterances to obtain the data from the user needed to complete the pizzaorder (e.g., toppings, time of delivery, any additional items to order,etc.). Another example may be the user invoking a quiz game skill, wheremultiple questions are asked of the user and the user responds withutterances that are processed by the system and whose text data is sentto the quiz show skill. Each utterance of the dialog may have a uniqueutterance ID but may also share a common dialog ID so that the systemcan process incoming audio data knowing that it is associated with aparticular dialog.

The NLU component 260 attempts to make a semantic interpretation of thephrases or statements represented in the text data input therein. Thatis, the NLU component 260 determines one or more meanings associatedwith the phrases or statements represented in the text data based onwords represented in the text data. The NLU component 260 determines anintent (e.g., intent data) representing an action that a user desires beperformed as well as pieces of the input text data that allow a device(e.g., the device 110, the remote system 120, the skill server(s), etc.)to execute the intent. For example, if the text data corresponds to“call John,” the NLU component 260 may determine an intent that thesystem establish a two-way communication channel between the device 110originating the call and a device of the recipient “John.” For furtherexample, if the text data corresponds to “tell John I am on my way,” theNLU component 260 may determine an intent that the system send a messageto a device of the recipient “John,” with the message corresponding to“I am on my way.”

The NLU component 260 outputs NLU results to the orchestrator component230. The NLU results may include an NLU hypothesis, including arepresentation of an intent and corresponding slotted data that may beused by a downstream component to perform the intent. Alternatively, theNLU results data may include multiple NLU hypotheses, with each NLUhypothesis representing an intent and corresponding slotted data. EachNLU hypothesis may be associated with a confidence value representing aconfidence of the NLU component 260 in the processing performed togenerate the NLU hypothesis associated with the confidence value.

The orchestrator component 230 may send the NLU results to an associatedskill component 290. If the NLU results include multiple NLU hypotheses,the orchestrator component 230 may send a portion of the NLU resultscorresponding to the top scoring NLU hypothesis to a skill component 290associated with the top scoring NLU hypothesis.

A “skill” or “skill component” may be software running on the remotesystem 120 that is akin to a software application running on atraditional computing device. That is, a skill component 290 may enablethe remote system 120 to execute specific functionality in order toperform one or more actions (e.g., provide information to a user,display content to a user, output music, or perform some other requestedaction). The remote system 120 may be configured with more than oneskill component 290. For example, a weather skill component may enablethe remote system 120 to provide weather information, a ride sharingskill component may enable the remote system 120 to schedule a trip withrespect to a ride sharing service, a restaurant skill component mayenable the remote system 120 to order food with respect to arestaurant's online ordering system, a communications skill componentmay enable the system to perform messaging or multi-endpointcommunications, etc. A skill component 290 may operate in conjunctionbetween the remote system 120 and other devices such as the device 110or skill server(s) 125 in order to complete certain functions. Inputs toa skill component 290 may come from various interactions and inputsources.

The functionality described herein as a skill or skill component may bereferred to using many different terms, such as an action, bot, app,application, speechlet or the like. A skill component 290 may includehardware, software, firmware, or the like that may be dedicated to theparticular skill component 290 or shared among different skillcomponents 290. A skill component 290 may be part of the remote system120 (as illustrated in FIG. 2) or may be located at whole (or in part)with one or more separate systems. Unless expressly stated otherwise,reference to a skill, skill device, or skill component may include askill component operating within the remote system 120 (for example asskill component 290) and/or skill component operating within a systemseparate from the remote system 120.

A skill component 290 may be configured to perform one or more actions.A skill may enable a skill component 290 to execute specificfunctionality in order to provide data or produce some other outputrequested by a user. A particular skill component 290 may be configuredto execute more than one skill. For example, a weather skill may involvea weather skill component providing weather information to the remotesystem 120, a ride sharing skill may involve a ride sharing skillcomponent scheduling a trip with respect to a ride sharing service, anorder pizza skill may involve a restaurant skill component orderingpizza with respect to a restaurant's online ordering system, etc.

A skill component 290 may implement different types of skills and mayoptionally be in communication with one or more skill server(s) 125. Theskill server(s) 125 may each correspond to a particular skill component290 and may be capable of performing operations to ultimately execute anaction. Types of skills include home automation skills (e.g., skillsthat enable a user to control home devices such as lights, door locks,cameras, thermostats, etc.), entertainment device skills (e.g., skillsthat enable a user to control entertainment devices such as smart TVs),video skills, flash briefing skills, gaming skills, as well as customskills that are not associated with any pre-configured type of skill. Insome instances, skill component(s) 290 or a skill server(s) 125 mayprovide output text data responsive to the present user command.

The remote system 120 may include a text-to-speech (TTS) component 280that generates audio data (e.g., synthesized speech) from text datausing one or more different methods. In one method of synthesis calledunit selection, the TTS component 280 matches text data against adatabase of recorded speech. The TTS component 280 selects matchingunits of recorded speech and concatenates the units together to formaudio data. In another method of synthesis called parametric synthesis,the TTS component 280 varies parameters such as frequency, volume, andnoise to create audio data including an artificial speech waveform.Parametric synthesis uses a computerized voice generator, sometimescalled a vocoder.

The remote system 120 may include profile storage 270. The profilestorage 270 may include a variety of information related to individualusers, groups of users, etc. that interact with the system. The profilestorage 270 may include one or more user profiles, with each userprofile being associated with a different user identifier. Each userprofile may include various user identifying information. Each userprofile may also include preferences of the user. Each user profile mayalso include one or more device identifiers, representing one or moredevices of the user.

The profile storage 270 may include one or more group profiles. Eachgroup profile may be associated with a different group identifier. Agroup profile may be specific to a group of users. That is, a groupprofile may be associated with two or more individual user profiles. Forexample, a group profile may be a household profile that is associatedwith user profiles associated with multiple users of a single household.A group profile may include preferences shared by all the user profilesassociated therewith. Each user profile associated with a group profilemay additionally include preferences specific to the user associatedtherewith. That is, each user profile may include preferences uniquefrom one or more other user profiles associated with the same groupprofile. A user profile may be a stand-alone profile or may beassociated with a group profile.

The system may be configured to incorporate user permissions and mayonly perform activities disclosed herein if approved by a user. As such,the systems, devices, components, and techniques described herein wouldbe typically configured to restrict processing where appropriate andonly process user information in a manner that ensures compliance withall appropriate laws, regulations, standards, and the like. The systemand techniques can be implemented on a geographic basis to ensurecompliance with laws in various jurisdictions and entities in which thecomponent(s) of the system(s) and/or user are located. Permissions maybe obtained from a user associated with the device 110, or other devicesdiscussed herein.

As described in greater detail below, the remote system 120 mayoptionally include a detector, such as system directed speech detector285, to determine if incoming audio data 211 actually includes speechintended for the system as operated by the remote system 120. If theincoming audio data 211 does include system-intended speech (for examplea command to the system, response to a previous command, information forthe system, a response to a system-managed communication from anotheruser, etc.), then the system may process such speech as it normallywould. If, however, the incoming audio data 211 does not includesystem-intended speech (for example background noise, speech coming froma television or other component, speech between persons not engagingwith a local device 110, etc.), then the system may discard that audiodata 211 and thus save computing resources by not performing furtherprocessing on the audio data 211.

While FIG. 2A illustrates the remote system 120 including the systemdirected speech detector 285, the disclosure is not limited thereto. Insome examples, the device 110 may include the system directed speechdetector 285 without departing from the disclosure. Thus, the device 110and/or the remote system 120 may include the system directed speechdetector 285 without departing from the disclosure.

The remote system 120 may include a user recognition component 295 thatrecognizes one or more users associated with data input to the system.The user recognition component 295 may take as input the audio data 211and/or text data output by the ASR component 250. The user recognitioncomponent 295 determines scores indicating whether user input originatedfrom a particular user. For example, a first score may indicate alikelihood that the user input originated from a first user, a secondscore may indicate a likelihood that the user input originated from asecond user, etc. The user recognition component 295 also determines anoverall confidence regarding the accuracy of user recognitionoperations. The user recognition component 295 may perform userrecognition by comparing audio characteristics in the audio data 211 tostored audio characteristics of users. The user recognition component295 may also perform user recognition by comparing biometric data (e.g.,fingerprint data, iris data, etc.), received by the system incorrelation with the present user input, to stored biometric data ofusers. The user recognition component 295 may further perform userrecognition by comparing image data (e.g., including a representation ofat least a feature of a user), received by the system in correlationwith the present user input, with stored image data includingrepresentations of features of different users. The user recognitioncomponent 295 may perform additional user recognition processes,including those known in the art. Output of the user recognitioncomponent 295 may include a single user identifier corresponding to themost likely user that originated the present user input. Alternatively,output of the user recognition component 295 may include an N-best listof user identifiers with respective scores indicating likelihoods ofrespective users originating the present user input. The output of theuser recognition component 295 may be used to inform NLU processing aswell as processing performed by other components of the system.

In some examples, the system 100 may perform remote speech processingusing the remote system 120 (e.g., the device 110 sends audio data tothe remote system 120 for speech processing). Thus, the device 110 mayinclude a wakeword detection component 220 and/or additional components(e.g., system directed speech detector 285) to identify audio data tosend to the remote system 120 for speech processing. However, thedisclosure is not limited thereto, and in other examples the system 100may perform both local and remote speech processing. For example, thedevice 110 may include a speech processing component 240 configured toperform limited speech processing prior to sending audio data to theremote system 120 for remote speech processing. The ASR data generatedby the limited speech processing component 240 may be used to identifydevice-directed speech, although the disclosure is not limited thereto.Finally, in some examples the system 100 may perform full local speechprocessing without departing from the disclosure. For example, thedevice 110 may include a speech processing component 240 configured toperform speech processing locally on the device 110, without sendingaudio data to the remote system 120, without departing from thedisclosure.

As the device 110 may be configured to perform local speech processing,FIG. 2B illustrates the device including all of the same components asthe remote system 120, and a description of these components with regardto the remote system 120 may also apply to the device 110 withoutdeparting from the disclosure. However, the disclosure is not limitedthereto and the device 110 may omit some of the components illustratedin FIG. 2B without departing from the disclosure. For example, thedevice 110 may include the wakeword detection component 220, the speechprocessing component 240, and the system directed speech detector 285,but may omit the orchestrator component 230, the profile storagecomponent 270, the TTS component 280, the skill component 290, and/orthe user recognition component 295 without departing from thedisclosure. While not illustrated in FIG. 2B, the device 110 may sendaudio data to the remote system 120 without departing from thedisclosure.

Example components for performing automatic speech recognition (ASR) areshown in FIG. 3A. As illustrated in FIG. 3A, an ASR component 250 mayconvert the audio data 211 into text. The ASR transcribes audio datainto text data representing the words of the speech contained in theaudio data. The text data may then be used by other components forvarious purposes, such as executing system commands, inputting data,etc. A spoken utterance in the audio data is input to a processorconfigured to perform ASR which then interprets the utterance based onthe similarity between the utterance and pre-established language models254 stored in an ASR model storage 252 c. For example, the ASR processmay compare the input audio data with models for sounds (e.g., subwordunits or phonemes) and sequences of sounds to identify words that matchthe sequence of sounds spoken in the utterance of the audio data.

The different ways a spoken utterance may be interpreted (i.e., thedifferent hypotheses) may each be assigned a probability or a confidencescore representing the likelihood that a particular set of words matchesthose spoken in the utterance. The confidence score may be based on anumber of factors including, for example, the similarity of the sound inthe utterance to models for language sounds (e.g., an acoustic model 253stored in an ASR Models Storage 252), and the likelihood that aparticular word which matches the sounds would be included in thesentence at the specific location (e.g., using a language or grammarmodel). Thus each potential textual interpretation of the spokenutterance (hypothesis) is associated with a confidence score. Based onthe considered factors and the assigned confidence score, the ASRprocess 250 outputs the most likely text recognized in the audio data.The ASR process may also output multiple hypotheses in the form of alattice or an N-best list with each hypothesis corresponding to aconfidence score or other score (such as probability scores, etc.).

The device or devices performing the ASR processing may include anacoustic front end (AFE) 256 and a speech recognition engine 258. Theacoustic front end (AFE) 256 transforms the audio data from themicrophone into data for processing by the speech recognition engine.The speech recognition engine 258 compares the speech recognition datawith acoustic models 253, language models 254, and other data models andinformation for recognizing the speech conveyed in the audio data. TheAFE may reduce noise in the audio data and divide the digitized audiodata into frames representing a time intervals for which the AFEdetermines a number of values, called features, representing thequalities of the audio data, along with a set of those values, called afeature vector, representing the features/qualities of the audio datawithin the frame. Many different features may be determined, as known inthe art, and each feature represents some quality of the audio that maybe useful for ASR processing. A number of approaches may be used by theAFE to process the audio data, such as mel-frequency cepstralcoefficients (MFCCs), perceptual linear predictive (PLP) techniques,neural network feature vector techniques, linear discriminant analysis,semi-tied covariance matrices, or other approaches known to those ofskill in the art.

The speech recognition engine 258 may process the output from the AFE256 with reference to information stored in speech/model storage (252).Alternatively, post front-end processed data (such as feature vectors)may be received by the device executing ASR processing from anothersource besides the internal AFE. For example, the device 110 may processaudio data into feature vectors (for example using an on-device AFE 256)and transmit that information to a server across a network 199 for ASRprocessing. Feature vectors may arrive at the server encoded, in whichcase they may be decoded prior to processing by the processor executingthe speech recognition engine 258.

The speech recognition engine 258 attempts to match received featurevectors to language phonemes and words as known in the stored acousticmodels 253 and language models 254. The speech recognition engine 258computes recognition scores for the feature vectors based on acousticinformation and language information. The acoustic information is usedto calculate an acoustic score representing a likelihood that theintended sound represented by a group of feature vectors matches alanguage phoneme. The language information is used to adjust theacoustic score by considering what sounds and/or words are used incontext with each other, thereby improving the likelihood that the ASRprocess will output speech results that make sense grammatically. Thespecific models used may be general models or may be modelscorresponding to a particular domain, such as music, banking, etc.

The speech recognition engine 258 may use a number of techniques tomatch feature vectors to phonemes, for example using Hidden MarkovModels (HMMs) to determine probabilities that feature vectors may matchphonemes. Sounds received may be represented as paths between states ofthe HMM and multiple paths may represent multiple possible text matchesfor the same sound.

Following ASR processing, the ASR results may be sent by the speechrecognition engine 258 to other processing components, which may belocal to the device performing ASR and/or distributed across thenetwork(s) 199. For example, ASR results in the form of a single textualrepresentation of the speech, an N-best list including multiplehypotheses and respective scores, lattice, confusion network, etc. maybe sent to NLU component 260 for further processing, such as conversionof the text into commands for execution, either by the device 110, bythe remote system 120, or by another device (such as a server running aspecific application like a search engine, etc.).

FIG. 3B illustrates how natural language processing is performed onaudio data.

Generally, the natural language component 260 attempts to make asemantic interpretation of text represented in text data (e.g., ASRresults 541 output by the speech recognition component 250). That is,the natural language component 260 determines the meaning behind thetext represented in text data based on the individual words. The naturallanguage component 260 interprets text to derive an intent or a desiredaction from the user as well as the pertinent pieces of information inthe text that allow a device (e.g., device 110) to complete that action.

The natural language component 260 may process text data includingseveral textual interpretations of a single utterance. For example, ifthe speech recognition component 250 outputs text data including anN-best list of textual interpretations, the natural language component260 may process the text data with respect to all (or a portion of) thetextual interpretations represented therein.

The natural language component 260 may include one or more recognizers363. Each recognizer 363 may be associated with a different “domain.” Adomain may correspond to a common group of information or activities,such as weather, music, video, communications, shopping, etc. Thenatural language component 260 may determine a domain potentiallyassociated with a textual interpretation represented in text data inputthereto in order to determine the proper recognizer 363 to process thetextual interpretation. The natural language component 260 may determinea single textual interpretation is potentially associated with more thanone domain. Multiple recognizers 263 may be functionally linked (e.g., atelephony/communications recognizer and a calendaring recognizer mayutilize data from the same contact list).

If the natural language component 260 determines a specific textualinterpretation is potentially associated with multiple domains, therecognizers 363 associated with the domains may process the specifictextual interpretation in parallel. For example, if a specific textualinterpretation potentially implicates both a communications domain and amusic domain, a recognizer associated with the communications domain mayprocess the textual interpretation in parallel, or substantially inparallel, with a recognizer associated with the music domain processingthe textual interpretation. The output generated by each recognizer 363may be scored, with the overall highest scored output from allrecognizers ordinarily being selected to be the correct result.

The natural language component 260 may communicate with various storagesto determine the potential domain(s) associated with a textualinterpretation. The natural language component 260 may communicate withthe natural language storage 373, which includes a databases of devices(374 a-374 n) identifying domains associated with specific devices. Forexample, the device 110 may be associated with domains for music,calendaring, contact lists, device-specific communications, etc. Inaddition, the natural language component 260 may communicate with anentity library 382, which includes database entries about specificservices on a specific device, either indexed by Device ID, Speaker ID,or Household ID, or some other indicator.

Each recognizer 363 may include a named entity recognition (NER)component 362. The NER component 362 attempts to identify grammars andlexical information that may be used to construe meaning with respect toa textual interpretation input therein. The NER component 362 identifiesportions of text represented in text data input into the naturallanguage component 260 that correspond to a named entity that may berecognizable by the system. The NER component 362 (or other component ofthe natural language component 260) may also determine whether a wordrefers to an entity that is not explicitly mentioned in the utterancetext, for example “him,” “her,” “it” or other anaphora, exophora or thelike.

Each recognizer 363, and more specifically each NER component 362, maybe associated with a particular grammar model and/or database 376, aparticular set of intents/actions 378, and a particular personalizedlexicon 386. Each gazetteer 384 may include domain-indexed lexicalinformation associated with a particular user and/or device. Forexample, the Gazetteer A (384 a) includes domain-index lexicalinformation 386 aa to 386 an. A user's music-domain lexical informationmight include album titles, artist names, and song names, for example,whereas a user's contact-list lexical information might include thenames of contacts. Since every user's music collection and contact listis presumably different, this personalized information improves entityresolution.

An NER component 362 applies grammar models 376 and lexical information386 associated with the domain (associated with the recognizer 363implementing the NER component 362) to determine a mention one or moreentities in a textual interpretation input therein. In this manner, theNER component 362 identifies “slots” (i.e., particular words in atextual interpretation) that may be needed for later command processing.The NER component 362 may also label each slot with a type of varyinglevels of specificity (e.g., noun, place, city, artist name, song name,etc.).

Each grammar model 376 includes the names of entities (i.e., nouns)commonly found in speech about the particular domain (i.e., genericterms) to which the grammar model 376 relates, whereas the lexicalinformation 386 is personalized to the user(s) and/or the device fromwhich the audio data 211 originated. For example, a grammar model 376associated with a shopping domain may include a database of wordscommonly used when people discuss shopping.

A downstream process called named entity resolution actually links aportion of text to an actual specific entity known to the system. Toperform named entity resolution, the natural language component 260 mayutilize gazetteer information (384 a-384 n) stored in an entity librarystorage 382. The gazetteer information 384 may be used to match textrepresented in text data output by the speech recognition component 250with different entities, such as song titles, contact names, etc.Gazetteers may be linked to users (e.g., a particular gazetteer may beassociated with a specific user's music collection), may be linked tocertain domains (e.g., shopping, music, video, communications, etc.), ormay be organized in a variety of other ways.

Each recognizer 263 may also include an intent classification (IC)component 364. The IC component 364 parses an input textualinterpretation to determine an intent(s) of the domain associated withthe recognizer 363 that potentially corresponds to the textualinterpretation. An intent corresponds to an action to be performed thatis responsive to the command represented by the textual interpretation.The IC component 364 may communicate with a database 378 of words linkedto intents. For example, a music intent database may link words andphrases such as “quiet,” “volume off,” and “mute” to a “mute” intent.The IC component 364 identifies potential intents by comparing words inthe textual interpretation to the words and phrases in an intentsdatabase 378 associated with the domain that is associated with therecognizer 363 implementing the IC component 364.

The intents identifiable by a specific IC component 364 are linked todomain-specific (i.e., the domain associated with the recognizer 363implementing the IC component 364) grammar frameworks 376 with “slots”to be filled. Each slot of a grammar framework 376 corresponds to aportion of the text interpretation that the system believes correspondsto an entity. For example, a grammar framework 376 corresponding to a<PlayMusic> intent may correspond to textual interpretation sentencestructures such as “Play {Artist Name},” “Play {Album Name},” “Play{Song name},” “Play {Song name} by {Artist Name},” etc. However, to makeresolution more flexible, grammar frameworks 376 may not be structuredas sentences, but rather based on associating slots with grammaticaltags.

For example, an NER component 362 may parse a textual interpretation toidentify words as subject, object, verb, preposition, etc. based ongrammar rules and/or models prior to recognizing named entities in thetextual interpretation. An IC component 364 (implemented by the samerecognizer 363 as the NER component 362) may use the identified verb toidentify an intent. The NER component 362 may then determine a grammarmodel 376 associated with the identified intent. For example, a grammarmodel 376 for an intent corresponding to <PlayMusic> may specify a listof slots applicable to play the identified “object” and any objectmodifier (e.g., a prepositional phrase), such as {Artist Name}, {AlbumName}, {Song name}, etc. The NER component 362 may then searchcorresponding fields in a lexicon 386 associated with the domainassociated with the recognizer 363 implementing the NER component 362,attempting to match words and phrases in the textual interpretation theNER component 362 previously tagged as a grammatical object or objectmodifier with those identified in the lexicon 386.

An NER component 362 may perform semantic tagging, which is the labelingof a word or combination of words according to their type/semanticmeaning. An NER component 362 may parse a textual interpretationheuristic grammar rules, or a model may be constructed using techniquessuch as hidden Markov models, maximum entropy models, log linear models,conditional random fields (CRF), and the like. For example, an NERcomponent 362 implemented by a music domain recognizer 363 may parse andtag a textual interpretation corresponding to “play mother's littlehelper by the rolling stones” as {Verb}: “Play,” {Object}: “mother'slittle helper,” {Object Preposition}: “by,” and {Object Modifier}: “therolling stones.” The NER component 362 identifies “Play” as a verb basedon a word database associated with the music domain, which an ICcomponent 364 (also implemented by the music domain recognizer 363) maydetermine corresponds to a <PlayMusic> intent. At this stage, nodetermination has been made as to the meaning of “mother's littlehelper” and “the rolling stones,” but based on grammar rules and models,the NER component 362 has determined that the text of these phrasesrelates to the grammatical object (i.e., entity) of the textualinterpretation.

The frameworks linked to the intent are then used to determine whatdatabase fields should be searched to determine the meaning of thesephrases, such as searching a user's gazetteer 384 for similarity withthe framework slots. For example, a framework for a <PlayMusic> intentmight indicate to attempt to resolve the identified object based {ArtistName}, {Album Name}, and {Song name}, and another framework for the sameintent might indicate to attempt to resolve the object modifier based on{Artist Name}, and resolve the object based on {Album Name} and {SongName} linked to the identified {Artist Name}. If the search of thegazetteer 384 does not resolve the a slot/field using gazetteerinformation, the NER component 362 may search the database of genericwords associated with the domain (in the knowledge base 372). Forexample, if the textual interpretation was “play songs by the rollingstones,” after failing to determine an album name or song name called“songs” by “the rolling stones,” the NER component 362 may search thedomain vocabulary for the word “songs.” In the alternative, genericwords may be checked before the gazetteer information, or both may betried, potentially producing two different results.

The natural language component 260 may tag the textual interpretation toattribute meaning to the textual interpretation. For example, thenatural language component 260 may tag “play mother's little helper bythe rolling stones” as: {domain} Music, {intent} Play Music, {artistname} rolling stones, {media type} SONG, and {song title} mother'slittle helper. For further example, the natural language component 260may tag “play songs by the rolling stones” as: {domain} Music, {intent}Play Music, {artist name} rolling stones, and {media type} SONG.

Each recognizer 363 may output data corresponding to a single textualinterpretation or to an N-best list of textual interpretations. Thenatural language component 260 may compile the output data of therecognizers 363 into a single cross-domain N-best list, and may sendcross-domain N-best list data 440 (representing the cross-domain N-bestlist) to a pruning component 450 (as illustrated in FIG. 4). The taggedtextual interpretations in the cross-domain N-best list data 440 mayeach be associated with a respect score indicating the tagged textualinterpretation corresponds to the domain associated with the recognizer363 from which the tagged textual interpretation was output. Forexample, the cross-domain N-best list data 440 may be represented as:

[0.95] Intent: <PlayMusic> ArtistName: Lady Gaga SongName: Poker Face

[0.70] Intent: <PlayVideo> ArtistName: Lady Gaga VideoName: Poker Face

[0.01] Intent: <PlayMusic> ArtistName: Lady Gaga AlbumName: Poker Face

[0.01] Intent: <PlayMusic> SongName: Pokerface

The pruning component 450 creates a new, shorter N-best list (i.e.,represented in cross-domain N-best list data 460 discussed below) basedon the cross-domain N-best list data 440. The pruning component 450 maysort the tagged textual interpretations represented in the cross-domainN-best list data 440 according to their respective scores.

The pruning component 450 may perform score thresholding with respect tothe cross-domain N-best list data 440. For example, the pruningcomponent 450 may select textual interpretations represented in thecross-domain N-best list data 440 associated with a score satisfying(e.g., meeting and/or exceeding) a score threshold. The pruningcomponent 450 may also or alternatively perform number of textualinterpretation thresholding. For example, the pruning component 450 mayselect the top scoring textual interpretation(s) associated with eachdifferent domain represented in the cross-domain N-best list data 440,with the new cross-domain N-best list data 460 including a total numberof textual interpretations meeting or falling below a threshold numberof textual interpretations. The purpose of the pruning component 450 isto create a new list of top scoring textual interpretations so thatdownstream (more resource intensive) processes may only operate on thetagged textual interpretations that most likely correspond to thecommand input to the system.

The natural language component 260 may also include a light slot fillercomponent 452. The light slot filler component 452 can take text fromslots represented in the textual interpretation(s) output by the pruningcomponent 450 and alter it to make the text more easily processed bydownstream components. The light slot filler component 452 may performlow latency operations that do not involve heavy operations such asreference to a knowledge base. The purpose of the light slot fillercomponent 452 is to replace words with other words or values that may bemore easily understood by downstream components. For example, if atextual interpretation includes the word “tomorrow,” the light slotfiller component 452 may replace the word “tomorrow” with an actual datefor purposes of downstream processing. Similarly, the light slot fillercomponent 452 may replace the word “CD” with “album” or the words“compact disc.” The replaced words are then included in the cross-domainN-best list data 460.

The natural language component 260 sends the cross-domain N-best listdata 460 to an entity resolution component 470. The entity resolutioncomponent 470 can apply rules or other instructions to standardizelabels or tokens from previous stages into an intent/slotrepresentation. The precise transformation may depend on the domain(e.g., for a travel domain the entity resolution component 470 maytransform a text mention of “Boston airport” to the standard BOSthree-letter code referring to the airport). The entity resolutioncomponent 470 can refer to an authority source (e.g., a knowledge base)that is used to specifically identify the precise entity referred to ineach slot of each textual interpretation represented in the cross-domainN-best list data 460. Specific intent/slot combinations may also be tiedto a particular source, which may then be used to resolve the text. Inthe example “play songs by the stones,” the entity resolution component470 may reference a personal music catalog, Amazon Music account, userprofile 602 (described herein), or the like. The entity resolutioncomponent 470 may output data including an altered N-best list that isbased on the cross-domain N-best list represented in the cross-domainN-best list data 460, but also includes more detailed information (e.g.,entity IDs) about the specific entities mentioned in the slots and/ormore detailed slot data that can eventually be used by a skill component290 which may be incorporated into the remote system 120 components orpipeline or may be on a separate device(s) in communication with theremote system 120. The natural language component 260 may includemultiple entity resolution components 470 and each entity resolutioncomponent 470 may be specific to one or more domains.

The entity resolution component 470 may not be successful in resolvingevery entity and filling every slot represented in the N-best listrepresented in the cross-domain N-best list data 460. This may result inthe entity resolution component 470 outputting incomplete results. Thenatural language component 260 may include a final ranker component 490,which may consider such errors when determining how to rank the taggedtextual interpretations for potential execution. For example, if a bookdomain recognizer 363 outputs a tagged textual interpretation includinga <ReadBook> intent flag, but the entity resolution component 470 cannotfind a book with a title matching the text of the item, the final rankercomponent 490 may re-score that particular tagged textual interpretationto be given a lower score. The final ranker component 490 may alsoassign a particular confidence to each tagged textual interpretationinput therein. The confidence score of a particular tagged textualinterpretation may be affected by whether the tagged textualinterpretation has unfilled slots. For example, if a tagged textualinterpretation associated with a first domain includes slots that areall filled/resolved, that tagged textual interpretation may beassociated with a higher confidence than another tagged textualinterpretation including at least some slots that areunfilled/unresolved.

The final ranker component 490 may apply re-scoring, biasing, or othertechniques to obtain the most preferred tagged and resolved textualinterpretation. To do so, the final ranker component 490 may considernot only the data output by the entity resolution component 470, but mayalso consider other data 491. The other data 491 may include a varietyof information. For example, the other data 491 may include skill ratingor popularity data. For example, if one skill (e.g., application) has aparticularly high rating, the final ranker component 490 may increasethe score of a textual interpretation(s) associated with or otherwiseinvoking that particular skill. The other data 491 may also includeinformation about skills that have been specifically enabled by theuser. For example, the final ranker component 490 may assign higherscores to textual interpretations associated with or otherwise invokingenabled skills than textual interpretations associated with or otherwiseinvoking non-enabled skills. User history may also be considered, suchas if the user regularly uses a particular supplemental skill or does soat particular times of day. Date, time, location, weather, type ofdevice 110, user ID, context, and other information may also beconsidered. For example, the final ranker component 490 may considerwhen any particular skills are currently active (e.g., music beingplayed, a game being played, etc.).

Following final ranking, the natural language component 260 may outputnatural language output data 485. The natural language component 260 maybe sent to the orchestrator component 230, which sends the naturallanguage output data 485 to an appropriate skill component 290 (e.g.,one configured to execute a command based on the textual interpretationrepresented in the natural language output data 485). The naturallanguage output data 485 may include an indicator of the intent of thetextual interpretation along with data associated with the intent, forexample an indication that the intent is <PlayMusic> and the music to beplayed is “Adele.” Multiple instances of natural language output data(e.g., 485 a-485 n) may be output for a given set of text data inputinto the natural language component 260.

The skill component(s) 290 provide the device 110/remote system 120 withcontent responsive to the natural language output data 485 receivedthereby. If the content is text data that needs to be converted tospeech, the orchestrator component 230 sends the content text data tothe text-to-speech component 280.

As noted above, many commands received by the system may have initiatedwith an utterance that included the wakeword, as detected by wakewordcomponent 220 of device 110 (explained above). In such instances, theaudio data 211 corresponding to the utterance may be sent (for exampleby the orchestrator 230) directly to the speech processing component 240for processing, and eventual execution, of the command in the utterance.In other circumstances, however, including those discussed below, thedevice 110 may send audio data to the remote system 120 even without thedevice 110 detecting a wakeword. For example, as explained below, incertain circumstances the remote system 120 may instruct a device 110 tosend to the remote system 120 audio data corresponding to captured audioeven if no wakeword is detected. In such circumstances, the system 100may optionally operate a detector, such as system directed speechdetector 285, to determine if incoming audio data 211 actually includesspeech intended for the system 100. If the incoming audio data 211 doesinclude system-intended speech (for example a command to the system,response to a previous command, information for the system, a responseto a system-managed communication from another user, etc.), then thesystem 100 may process such speech as it normally would. If, however,the incoming audio data 211 does not include system-intended speech (forexample background noise, speech coming from a television or othercomponent, speech between persons not engaging with a local device 110,etc.), then the system 100 may discard that audio data 211 and thus savecomputing resources by not performing further processing on the audiodata 211. While the system directed speech detector 285 may not be asnecessary when the device 110 has first detected a wakeword prior tosending the audio data 211, the system directed speech detector 285 maysave computing resources in filtering out non-wakeword non-systemdirected speech from non-wakeword system directed speech. (Though thesystem directed speech detector 285 may also be used as a wakewordconfirmation component and thus may operate on audio data 211 that wassent post-wakeword detection and/or on audio data 211 that was sentwithout wakeword detection.)

While the above description refers to the remote system 120 instructingthe device 110 to send the audio data to the remote system 120 even ifno wakeword is detected, the disclosure is not limited thereto. In someexamples, the system directed speech detector 285 may be located on thedevice 110 and the device 110 may determine to send audio data to theremote system 120 (e.g., without an explicit instruction from the remotesystem 120 to do so), even if no wakeword is detected, without departingfrom the disclosure. Additionally or alternatively, the system directedspeech detector 285 and the speech processing component 240 may belocated on the device 110 and the device 110 may perform speechprocessing on the audio data (e.g., without sending the audio data tothe remote system 120), even if no wakeword is detected, withoutdeparting from the disclosure.

Configuration and operation of the system directed speech detector 285is illustrated in FIGS. 5A and 5B. As shown in FIG. 5A, the systemdirected speech detector 285 may include a number of differentcomponents. First, the system directed speech detector 285 may include avoice activity detector (VAD) 520. The VAD 520 may operate to detectwhether the incoming audio data 211 includes speech or not. The VADoutput 521 may be a binary indicator. Thus, if the incoming audio data211 includes speech, the VAD 520 may output an indicator 521 that theaudio data 211 does includes speech (e.g., a 1) and if the incomingaudio data 211 does not includes speech, the VAD 520 may output anindicator 521 that the audio data 211 does not includes speech (e.g., a0). The VAD output 521 may also be a score (e.g., a number between 0and 1) corresponding to a likelihood that the audio data 211 includesspeech. The VAD 520 may also perform start-point detection as well asend-point detection where the VAD 520 determines when speech starts inthe audio data 211 and when it ends in the audio data 211. Thus the VADoutput 521 may also include indicators of a speech start point and/or aspeech endpoint for use by other components of the system. (For example,the start-point and end-points may demarcate the audio data 211 that issent to the speech processing component 240.) The VAD output 521 may beassociated with a same unique ID as the audio data 211 for purposes oftracking system processing across various components.

The VAD 520 may operate using a variety of VAD techniques, includingthose described above with regard to VAD operations performed by device110. The VAD may be configured to be robust to background noise so as toaccurately detect when audio data actually includes speech or not. TheVAD 520 may operate on raw audio data 211 such as that sent by device110 or may operate on feature vectors or other data representing theaudio data 211. For example, the VAD 520 may take the form of a deepneural network (DNN) and may operate on a single feature vectorrepresenting the entirety of audio data 211 received from the device ormay operate on multiple feature vectors, for example feature vectorsrepresenting frames of audio data where each frame covers a certainamount of time of audio data (e.g., 25 ms). The VAD 520 may also operateon other data 581 that may be useful in detecting voice activity in theaudio data 211. For example, the other data 581 may include results ofanchored speech detection where the system takes a representation (suchas a voice fingerprint, reference feature vector, etc.) of a referencesection of speech (such as speech of a voice that uttered a previouscommand to the system that included a wakeword) and compares a voicedetected in the audio data 211 to determine if that voice matches avoice in the reference section of speech. If the voices match, that maybe an indicator to the VAD 520 that speech was detected. If not, thatmay be an indicator to the VAD 520 that speech was not detected. (Forexample, referring to FIG. 7 below, a representation may be taken ofvoice data in the first input audio data which may then be compared tothe second input audio data to see if the voices match. If they do (ordo not) that information may be considered by the VAD 520.) The VAD 520may also consider other data when determining if speech was detected.The VAD 520 may also consider speaker ID information (such as may beoutput by user recognition component 295), directionality data that mayindicate what direction (relative to the capture device 110) theincoming audio was received from. Such directionality data may bereceived from the device 110 and may have been determined by abeamformer or other component of device 110. The VAD 520 may alsoconsider data regarding a previous utterance which may indicate whetherthe further audio data received by the system is likely to includespeech. Other VAD techniques may also be used.

If the VAD output 521 indicates that no speech was detected the system(through orchestrator 230 or some other component) may discontinueprocessing with regard to the audio data 211, thus saving computingresources that might otherwise have been spent on other processes (e.g.,ASR for the audio data 211, etc.). If the VAD output 521 indicates thatspeech was detected, the system may make a determination as to whetherthe speech was or was not directed to the speech-processing system. Sucha determination may be made by the system directed detector 540. Thesystem directed detector 540 may include a trained model, such as a DNN,that operates on a feature vector which represent certain data that maybe useful in determining whether or not speech was directed to thesystem. To create the feature vector operable by the system directeddetector 540, a feature extractor 530 may be used. The feature extractor530 may input ASR results 541 which include results from the processingof the audio data 211 by the speech recognition component 250.

The ASR results 541 may include an N-best list of top scoring ASRhypotheses and their corresponding scores, portions (or all of) an ASRlattice/trellis with scores, portions (or all of) an ASR search graphwith scores, portions (or all of) an ASR confusion network with scores,or other such ASR output. As an example, the ASR results 541 may includea trellis, which may include a raw search graph as scored during ASRdecoding. The ASR results 541 may also include a lattice, which may be atrellis as scored that has been pruned to remove certain hypotheses thatdo not exceed a score threshold or number of hypotheses threshold. TheASR results 541 may also include a confusion network where paths fromthe lattice have been merged (e.g., merging hypotheses that may shareall or a portion of a same word). The confusion network may be a datastructure corresponding to a linear graph that may be used as analternate representation of the most likely hypotheses of the decoderlattice. The ASR results 541 may also include corresponding respectivescores (such as for a trellis, lattice, confusion network, individualhypothesis, N-best list, etc.)

The ASR results 541 (or other data 591) may include other ASR resultrelated data such as other features from the ASR system or datadetermined by another component. For example, the system may determinean entropy of the ASR results (for example a trellis entropy or thelike) that indicates a how spread apart the probability mass of thetrellis is among the alternate hypotheses. A large entropy (e.g., largespread of probability mass over many hypotheses) may indicate the ASRcomponent 250 being less confident about its best hypothesis, which inturn may correlate to detected speech not being device directed. Theentropy may be a feature included in other data 591 to be considered bythe system directed detector 540.

The system may also determine and consider ASR decoding costs, which mayinclude features from Viterbi decoding costs of the ASR. Such featuresmay indicate how well the input acoustics and vocabulary match with theacoustic models 253 and language models 254. Higher Viterbi costs mayindicate greater mismatch between the model and the given data, whichmay correlate to detected speech not being device directed. Confusionnetwork feature may also be used. For example, an average number of arcs(where each arc represents a word) from a particular node (representinga potential join between two words) may measure how many competinghypotheses there are in the confusion network. A large number ofcompeting hypotheses may indicate that the ASR component 250 is lessconfident about the top hypothesis, which may correlate to detectedspeech not being device directed. Other such features or data from theASR results 541 may also be used as other data 591.

The ASR results 541 may be included in a system directed detector (SDD)feature vector 531 that can be used to determine whether speech wassystem-directed. Such ASR results may be helpful in determining ifspeech was system-directed. For example, if ASR results include a highscoring single hypothesis, that may indicate that the speech representedin the audio data 211 was directed at, and intended for, the device 110.If, however, ASR results do not include a single high scoringhypothesis, but rather many lower scoring hypotheses, that may indicatesome confusion on the part of the speech recognition component 250 andmay also indicate that the speech represented in the audio data 211 wasnot directed at, nor intended for, the device 110.

The ASR results 541 may include complete ASR results, for example ASRresults corresponding to all speech between a startpoint and endpoint(such as a complete lattice, etc.). In this configuration the system maywait until all ASR processing for a certain input audio has beencompleted before operating the feature extractor 530 and system directeddetector 540. Thus the system directed detector 540 may receive a SDDfeature vector 531 that includes all the representations of the audiodata 211 created by the feature extractor 530. The system directeddetector 540 may then operate a trained model (such as a DNN) on the SDDfeature vector 531 to determine a score corresponding to a likelihoodthat the audio data 211 includes a representation of system-directedspeech. If the score is above a threshold, the system directed detector540 may determine that the audio data 211 does include a representationof system-directed speech. The SDD result 551 may include an indicatorof whether the audio data includes system-directed speech, a score,and/or some other data.

The ASR results 541 may also include incomplete ASR results, for exampleASR results corresponding to only some speech between a between astartpoint and endpoint (such as an incomplete lattice, etc.). In thisconfiguration the feature extractor 530/system directed detector 540 maybe configured to operate on incomplete ASR results 541 and thus thesystem directed detector 540 may be configured to output an SSD result551 that provides an indication as to whether the portion of audio dataprocessed (that corresponds to the incomplete ASR results) correspondsto system directed speech. The system may thus be configured to performASR at least partially in parallel with the system directed detector 540to process ASR result data as it is ready and thus continually update anSDD result 551. Once the system directed speech detector 285 hasprocessed enough ASR results and/or the SDD result 551 exceeds athreshold, the system may determine that the audio data 211 includessystem-directed speech. Similarly, once the system directed speechdetector 285 has processed enough ASR results and/or the SDD result 551drops below another threshold, the system may determine that the audiodata 211 does not include system-directed speech.

The SDD result 551 may be associated with a same unique ID as the audiodata 211 and VAD output 521 for purposes of tracking system processingacross various components.

The feature extractor 530 may also incorporate in an SDD feature vector531 representations of other data 591. Other data 591 may include, forexample, word embeddings from words output by the speech recognitioncomponent 250 may be considered. Word embeddings are vectorrepresentations of words or sequences of words that show how specificwords may be used relative to other words, such as in a large textcorpus. A word embedding may be of a different length depending on howmany words are in a text segment represented by the word embedding. Forpurposes of the feature extractor 530 processing and representing a wordembedding in an SDD feature vector 531 (which may be of a fixed length),a word embedding of unknown length may be processed by a neural networkwith memory, such as an LSTM (long short term memory) network. Eachvector of a word embedding may be processed by the LSTM which may thenoutput a fixed representation of the input word embedding vectors.

Other data 591 may also include, for example, NLU output from thenatural language 260 component may be considered. Thus, if naturallanguage output data 485 indicates a high correlation between the audiodata 211 and an out-of-domain indication (e.g., no intent classifierscores from ICs 364 or overall domain scores from recognizers 363 reacha certain confidence threshold), this may indicate that the audio data211 does not include system-directed speech. Other data 591 may alsoinclude, for example, an indicator of a user/speaker as output userrecognition component 295. Thus, for example, if the user recognitioncomponent 295 does not indicate the presence of a known user, orindicates the presence of a user associated with audio data 211 that wasnot associated with a previous utterance, this may indicate that theaudio data 211 does not include system-directed speech. The other data591 may also include an indication that a voice represented in audiodata 211 is the same (or different) as the voice detected in previousinput audio data corresponding to a previous utterance.

Other data 591 may also include image data. For example, if image datais detected from one or more devices that are nearby to the device 110(which may include the device 110 itself) that captured the audio databeing processed using the system directed speech detector (285), theimage data may be processed to determine whether a user is facing anaudio capture device for purposes of determining whether speech issystem-directed.

Other data 591 may also dialog history data. For example, the other data591 may include information about whether a speaker has changed from aprevious utterance to the current audio data 211, whether a topic ofconversation has changed from a previous utterance to the current audiodata, how NLU results from a previous utterance compare to NLU resultsobtained using the current audio data 211, other system contextinformation. The other data 591 may also include an indicator as towhether the audio data 211 was received as a result of a wake command orwhether the audio data 211 was sent without the device 110 detecting awake command (e.g., the device 110 being instructed by remote system 120and/or determining to send the audio data without first detecting a wakecommand).

Other data 591 may also include information from the user profile.

Other data 591 may also include direction data, for example dataregarding a direction of arrival of speech detected by the device, forexample a beam index number, angle data, or the like. If second audiodata is received from a different direction than first audio data (suchas the audio data explained below in reference to FIGS. 7A-7C), then thesystem may be less likely to declare the second audio data to includesystem-directed speech since it is originating from a differentlocation.

Other data 591 may also include acoustic feature data such as pitch,prosody, intonation, volume, or other data descriptive of the speech inthe audio data 211. As a user may use a different vocal tone to speakwith a machine than with another human, acoustic feature information maybe useful in determining if speech is device-directed.

Other data 591 may also include an indicator that indicates whether theaudio data 211 includes a wakeword. For example, if a device 110 detectsa wakeword prior to sending the audio data 211 to the remote system 120,the device 110 may send along an indicator that the device 110 detecteda wakeword in the audio data 211. In another example, the remote system120 may include another component that processes incoming audio data 211to determine if it includes a wakeword. If it does, the component maycreate an indicator indicating that the audio data 211 includes awakeword. The indicator may then be included in other data 591 to beincorporated in the feature vector 531 and/or otherwise considered bythe system directed detector 540.

Other data 591 may also include device history data such as informationabout previous operations related to the device 110 that sent the audiodata 211. For example, the other data 591 may include information abouta previous utterance that was just executed, where the utteranceoriginated with the same device 110 as a current utterance and theprevious utterance was within a certain time window of the currentutterance. Device history data may be stored in a manner associated withthe device identifier (which may also be included in other data 591),which may also be used to track other information about the device, suchas device hardware, capability, location, etc.

The other data 581 used by the VAD 520 may include similar data and/ordifferent data from the other data 591 used by the feature extractor530. The other data 581/591 may thus include a variety of datacorresponding to input audio from a previous utterance. That data mayinclude acoustic data from a previous utterance, speaker ID/voiceidentification data from a previous utterance, information about thetime between a previous utterance and a current utterance, or a varietyof other data described herein taken from a previous utterance. A scorethreshold (for the system directed detector 540 and/or the VAD 520) maybe based on the data from the previous utterance. For example, a scorethreshold (for the system directed detector 540 and/or the VAD 520) maybe based on acoustic data from a previous utterance.

The feature extractor 530 may output a single SDD feature vector 531 forone utterance/instance of input audio data 511. The SDD feature vector531 may consistently be a fixed length, or may be a variable lengthvector depending on the relevant data available for particular audiodata 211. Thus, the system directed detector 540 may output a single SDDresult 551 per utterance/instance of input audio data 511. The SDDresult 551 may be a binary indicator. Thus, if the incoming audio data211 includes system-directed speech, the system directed detector 540may output an indicator 551 that the audio data 211 does includessystem-directed speech (e.g., a 1) and if the incoming audio data 211does not includes system-directed speech, the system directed detector540 may output an indicator 551 that the audio data 211 does notsystem-directed includes speech (e.g., a 0). The SDD result 551 may alsobe a score (e.g., a number between 0 and 1) corresponding to alikelihood that the audio data 211 includes system-directed speech.Although not illustrated in FIG. 5A, the flow of data to and from thesystem directed speech detector 285 may be managed by the orchestrator230 or by one or more other components.

The trained model(s) of the system directed detector 540 may be trainedon many different examples of SDD feature vectors that include bothpositive and negative training samples (e.g., samples that bothrepresent system-directed speech and non-system directed speech) so thatthe DNN and/or other trained model of the system directed detector 540may be capable of robustly detecting when speech is system-directedversus when speech is not system-directed.

The process for determine whether incoming audio data 211 includessystem-directed speech (for example using system directed speechdetector 285) is illustrated in FIG. 5B. As shown, the system detects(560) if there is voice activity in the detected audio data 211, forexample using VAD 520. If there is no voice activity detected (560:No)(e.g. VAD output 521 indicates no voice activity), the system may waitand determine whether there is voice activity detected in subsequentincoming audio data (e.g., loop and repeat step 560). While notillustrated in FIG. 5B, if there is no voice activity detected in asegment of the incoming audio data 211, then the system may not performadditional processing (e.g., ASR and/or NLU processing) on the segmentand may discard the segment of the incoming audio data.

If there is voice activity detected (560:Yes) (e.g. VAD output 521indicates voice activity), the system may send (562) the audio data forASR/NLU processing by the speech processing components 240. The systemthen determines whether (564) detected speech is system-directed, forexample using the feature extractor 5 and system directed detector 540.If the speech is not determined to be system-directed (564:No) (e.g. SDDresult 551 indicates no system-directed speech), the system may cancel(566) further processing for the audio data. If the speech is determinedto be system-directed (564:Yes) (e.g. SDD result 551 indicatessystem-directed speech), the system may cause (568) execution of speechprocessing results which may include continuing speech processing (e.g.,NLU processing) if not already complete, sending speech processingresults to further components such as a skill component 290 for furtheraction, etc. The system may also update the system context to reflectactions taken by the system since detecting the audio data 211 andprocessing the various ASR and/or NLU results.

FIG. 6 illustrates the user profile storage 270 that includes dataregarding customer profiles as well as individual user profiles 602. Forillustration, as shown in FIG. 6, each user profile 602 may includeinformation indicating system executable commands that are enabled withrespect to the user profile. Each enabled command may be associated witha user preference regarding whether a device should remain connected tothe server after content responsive to the command is output by thedevice. Moreover, an enabled command associated with a user preferenceindicating a device's connection to the server may additionally beassociated with a user preference regarding how long the device shouldbe connected to the server prior to the device re-entering wakeworddetection mode and again requiring the user speak a wakeword to input acommand. A user profile may also include data regarding other userspecific features such as likelihood of the user speaking multiplecommands in succession, the user's dialog history regarding previousutterances spoken to the system, etc. Each user profile 602 mayadditionally include other data not explicitly illustrated.

A device 110 may be configured, under certain circumstances, to captureaudio using a microphone and begin sending audio data corresponding tothe audio to the remote system 120 without detecting a wake command. Forexample, if the system determines that the user is likely to speak acommand to the system, the remote system 120 may send an instruction toa local device 110 to enable a microphone and send audio data to theremote system 120, even without first detecting a wake command. Adetermination of such a likelihood may happen at a certain time, withcertain users, under certain conditions, etc. In one example, a user mayspeak a first utterance that includes a wakeword, and based on the firstutterance, the system may direct a device 110 to allow audio data tocontinue to be sent to the remote system 120, even after completion ofexecution of a command of the first utterance.

FIGS. 7A-7C are signal flow diagrams illustrating the processingperformed when a remote system detects system-directed speechrepresented in input audio data and performs speech processing on theinput audio data according to embodiments of the present disclosure. Asillustrated in FIGS. 7A-7C, the system 100 may receive a firstutterance, process that utterance and then subsequently instruct thedevice 110 to continue to send further audio data to the remote system120, even absent a wake command. The system 100 then processes theadditional audio data from the device 110 to determine that it includessystem-directed speech.

As illustrated in FIG. 7A, a device 110 receives (702) first input audiocorresponding to an utterance that includes a wakeword. The device 110generates (704) first input audio data corresponding to the first inputaudio and sends (706) the first input audio data to the remote system120.

The remote system 120 performs (708) speech processing on the firstinput audio data to determine a first command. The remote system 120then determines (710) first content responsive to the first command. Theremote system 120 may determine the first content using data availablewithin the remote system 120. Alternatively, the remote system 120 maydetermine the remote system 120 should invoke a skill component 290associated with a skill server(s) 125 (e.g., content source server(s))to determine the first content. In such a situation, the remote system120 may send (712) a request for content responsive to the first commandto the skill server(s) 125. The skill server(s) 125 may determine (714)first content data corresponding to the first content and the remotesystem 120 may receive (716) the first content data from the skillserver(s) 125. Additionally or alternatively, the remote system 120 maydetermine the first content data without departing from the disclosure.

If content data is received as text data, the remote system 120 mayperform text-to-speech processing on the text data to generate (718)first output audio data and send (720) the first output audio data tothe device. In some examples, the remote system 120 may alternativelyreceive the first content data as audio data, in which case the remotesystem may 120 simply send the received first content data to the device110 as the first output audio data in step 720. Additionally oralternatively, the remote system 120 may send the first content data tothe device 110 and the device 110 may perform text-to-speech processingon the first content data to generate the first output audio datawithout departing from the disclosure.

The remote system 120 may also send (722) an instruction to the device110 to send further input audio data corresponding to further capturedaudio without detecting a wake command even though the system does notneed further user input to complete processing of the initial command.For example, the instruction may instruct the device 110 to send thefirst thirty (30) seconds of audio without detecting a wake command.However, the disclosure is not limited thereto and the duration of timemay vary (e.g., 10 seconds, 15 seconds, etc.) without departing from thedisclosure. For example, the remote system 120 may determine theduration of time based on the first command, the first output audiodata, and/or the like without departing from the disclosure.Additionally or alternatively, the instruction may instruct the device110 to stop sending audio data if noise above a certain volume is notheard after a certain amount of time. In some examples, the instructionmay instruct the device 110 to send further input audio data until theremote system 120 sends a second instruction to stop sending the furtherinput audio data. For example, the device 110 may send further inputaudio data until the device 110 receives the second instruction and/orthe duration of time has elapsed (e.g., timeout event occurs), althoughthe disclosure is not limited thereto.

The device 110 may also activate an indicator to indicate that audiodata is being sent to the remote system 120. Thus the remote system 120may further instruct the device 110 to reactivate the light indicatoronce content responsive to a command is output. The remote system 120instructs the device 110 to, once again, deactivate the light indicatoronce a time out period has transpired after the device is instructed tosend audio data without first detecting a wake command.

The device 110 may output (724) audio corresponding to the first outputaudio data. As shown in FIG. 7B, the device 110 may detect (726) secondinput audio, generate (728) second input audio data corresponding to thesecond input audio, and send (730) second input audio data correspondingto subsequently captured audio to the remote system 120 without firstdetecting a wake command.

Upon receiving the second input audio data, the remote system 120determines whether the second input audio data includes system-directedspeech, for example using system directed speech detector 285. Todetermine whether the second input audio data includes system-directedspeech, the system first may first perform (732) VAD on the second inputaudio data as described herein, for example using VAD 520. The remotesystem 120 may then perform (734) ASR on the second input audio data todetermine ASR results. The server 120 may then determine (736) that thespeech in the second input audio data is system-directed speech, forexample using system directed detector 540 as described above. If thespeech is system-directed, the server may perform (738) NLU using ASRresults to determine a second command. The server may then cause thesecond command to be executed, for example as shown in FIG. 7C.

As shown in FIG. 7C, the remote system 120 may determine (740) secondcontent responsive to the second command. The remote system 120 maydetermine the second content using data available within the remotesystem 120. Alternatively, the remote system 120 may determine theremote system 120 should invoke a skill component 290 that may beassociated with skill server(s) 125 (e.g., content source server(s)) todetermine the second content. In such a situation, the remote system 120may send (742) a request for content responsive to the second command tothe skill server(s) 125. The skill server(s) 125 may determine (744)second content data corresponding to the second content and the remotesystem 120 may receive (746) the second content data from the skillserver(s) 125. Additionally or alternatively, the remote system 120 maydetermine the second content data without departing from the disclosure.

If content data is received as text data, the remote system 120 mayperform text-to-speech processing on the text data to generate (748)second output audio data and may send (750) the second output audio datato the device 110. In some examples, the remote system 120 mayalternatively receive the second content data as audio data, in whichcase the remote system may 120 simply send the received second contentdata to the device 110 as the second output audio data in step 750.Additionally or alternatively, the remote system 120 may send the secondcontent data to the device 110 and the device 110 may performtext-to-speech processing on the second content data to generate thesecond output audio data without departing from the disclosure.

The device 110 may then output (752) audio corresponding to the secondoutput audio data. As the system is engaged in different rounds ofspeech processing, the system may assign different unique ID numbers tothe first input audio data and the second input audio data. In thismanner, the system can track processing and results across components(such as components illustrated in FIGS. 2-5A, etc.) and can coordinatesystem activity relative to the first or second input audio data usingthe unique ID. For example, if the system determines that the secondinput audio does not include system directed speech (e.g., 564:No), thesystem may cancel (566) further processing for data in the systemrelated to the identifier assigned to the second input audio data.

Although FIG. 7B illustrates determining whether second input audio dataincludes system-directed speech, the audio data so processed by thesystem need not necessarily be audio data that is received following afirst command. The audio data processed to determine if it includessystem-directed speech, for example using components discussed withregard to FIG. 5A and a method discussed with regard to FIG. 5B may beaudio data that is received from a device 110 under a variety ofdifferent circumstances.

Although the certain descriptions above illustrate the techniquesperformed with regard to audio data triggered by a wakeword, thetechniques may apply to any “wake” command that instructs a device tosend audio data to the server. For example, a button push, gesture, orother action may be considered a wake command. Any wake command may besubstituted for a wakeword herein. Thus, for any instance herein of thesystem instructing a device to send (or to cease sending) audio datawithout first detecting a wakeword may also be considered instructingthe device to send (or cease sending) audio data without first detectingany wake command.

Various machine learning techniques may be used to train and operatemodels to operate various components and perform various steps describedabove, such as voice activity detection, system directed detection, userrecognition, etc. Models may be trained and operated according tovarious machine learning techniques. Such techniques may include, forexample, neural networks (such as deep neural networks and/or recurrentneural networks), inference engines, trained classifiers, etc. Examplesof trained classifiers include Support Vector Machines (SVMs), neuralnetworks (such as deep neural networks (DNNs)), decision trees, AdaBoost(short for “Adaptive Boosting”) combined with decision trees, and randomforests. Focusing on SVM as an example, SVM is a supervised learningmodel with associated learning algorithms that analyze data andrecognize patterns in the data, and which are commonly used forclassification and regression analysis. Given a set of trainingexamples, each marked as belonging to one of two categories, an SVMtraining algorithm builds a model that assigns new examples into onecategory or the other, making it a non-probabilistic binary linearclassifier. More complex SVM models may be built with the training setidentifying more than two categories, with the SVM determining whichcategory is most similar to input data. An SVM model may be mapped sothat the examples of the separate categories are divided by clear gaps.New examples are then mapped into that same space and predicted tobelong to a category based on which side of the gaps they fall on.Classifiers may issue a “score” indicating which category the data mostclosely matches. The score may provide an indication of how closely thedata matches the category.

In order to apply the machine learning techniques, the machine learningprocesses themselves need to be trained. Training a machine learningcomponent such as, in this case, one of the first or second models,requires establishing a “ground truth” for the training examples. Inmachine learning, the term “ground truth” refers to the accuracy of atraining set's classification for supervised learning techniques.Various techniques may be used to train the models includingbackpropagation, statistical learning, supervised learning,semi-supervised learning, stochastic learning, or other knowntechniques.

While the above description refers to the remote system 120 instructingthe device 110 to send the audio data to the remote system 120 even ifno wakeword is detected, the disclosure is not limited thereto. In someexamples, the system directed speech detector 285 may be located on thedevice 110 and the device 110 may determine to send audio data to theremote system 120 (e.g., without an explicit instruction from the remotesystem 120 to do so), even if no wakeword is detected, without departingfrom the disclosure. Additionally or alternatively, the system directedspeech detector 285 and the speech processing component 240 may belocated on the device 110 and the device 110 may perform speechprocessing on the audio data (e.g., without sending the audio data tothe remote system 120), even if no wakeword is detected, withoutdeparting from the disclosure.

Thus, while FIGS. 7A-7C illustrate examples in which the remote system120 detects system-directed speech, the disclosure is not limitedthereto. In some examples, the device 110 may detect system-directedspeech and send audio data to the remote system 120 for speechprocessing, as illustrated in FIGS. 8A-8C. Additionally oralternatively, in some examples the device 110 may detectsystem-directed speech and perform local speech processing on the audiodata without departing from the disclosure, as illustrated in FIGS.9A-9B. As FIGS. 8A-8C and 9A-9B illustrate steps described in detailabove with regard to FIGS. 7A-7C, a redundant description is omitted.Thus, regardless of whether a step is performed by the device 110 and/orthe remote system 120, a description of a step illustrated in FIGS.7A-7C may apply to similar steps illustrated in FIGS. 8A-8C and 9A-9Bwithout departing from the disclosure.

FIGS. 8A-8C are signal flow diagrams illustrating the processingperformed when a device detects system-directed speech represented ininput audio data and sends the input audio data to a remote system forspeech processing according to embodiments of the present disclosure. Asillustrated in FIG. 8A, the device 110 may receive (802) first inputaudio corresponding to an utterance with a wake command (e.g., firstinput audio includes a representation of a wakeword), may generate (804)first input audio data corresponding to the first input audio, and maysend (806) the first input audio data to the remote system 120.

The remote system 120 may perform (808) speech processing on the firstinput audio data to determine a first command, may determine (810) firstcontent responsive to the first command, and may optionally send (812) arequest for the first content to the skill server(s) 125. If the remotesystem 120 sends the request, the skill server(s) 125 may determine(813) first content data corresponding to the first content and theremote system 120 may receive (814) the first content data from theskill server(s) 125. Additionally or alternatively, the remote system120 may determine the first content data without departing from thedisclosure.

In some examples, the remote system 120 may generate (816) the firstoutput audio data (e.g., perform text-to-speech processing on the firstcontent data) and may send (818) the first output audio data to thedevice 110. However, the remote system 120 may alternatively receive thefirst content data as audio data, in which case the remote system may120 simply send the received first content data to the device 110 as thefirst output audio data in step 818. Additionally or alternatively, theremote system 120 may send the first content data to the device 110 andthe device 110 may perform text-to-speech processing on the firstcontent data to generate the first output audio data without departingfrom the disclosure. The device 110 may then output (820) audiocorresponding to the first output audio data.

As illustrated in FIG. 8B, while the device 110 is outputting the audiocorresponding to the first output audio data in step 820, the device 110may detect (822) second input audio, may generate (824) second inputaudio data corresponding to the second input audio, may perform (826)voice activity detection (VAD) processing on the second input audio datato determine that speech is detected, may perform (828) automatic speechrecognition (ASR) processing on the second input audio data, maydetermine (830) that the speech represented in the second input audiodata is system-directed (e.g., device-directed speech or device-directedspeech event), and may send (832) the second input audio data to theremote system 120 when system-directed speech is detected. Thus, thedevice 110 may send the second input audio data without detecting a wakecommand (e.g., wakeword not represented in the second input audio data),although the disclosure is not limited thereto.

The remote system 120 may perform (834) ASR processing on the secondinput audio data and may perform (836) NLU processing using the ASRresults (e.g., ASR data) to determine a second command represented inthe second input audio data. Thus, in the example illustrated in FIG.8B, the device 110 may perform some speech processing locally in step828, which may assist the device 110 in detecting system-directed speechin step 830, while the remote system 120 may also perform speechprocessing remotely in step 834.

As illustrated in FIG. 8C, the remote system 120 may determine (838)second content responsive to the second command and may optionally send(840) a request for the second content to the skill server(s) 125. Ifthe remote system 120 sends the request, the skill server(s) 125 maydetermine (841) second content data corresponding to the second contentand the remote system 120 may (842) receive the second content data fromthe skill server(s) 125. Additionally or alternatively, the remotesystem 120 may determine the second content data without departing fromthe disclosure.

The remote system 120 may generate (844) second output audio data andmay send (846) the second output audio data to the device 110. In someexamples, the remote system 120 may alternatively receive the secondcontent data as audio data, in which case the remote system may 120simply send the received second content data to the device 110 as thesecond output audio data in step 846. Additionally or alternatively, theremote system 120 may send the second content data to the device 110 andthe device 110 may perform text-to-speech processing on the secondcontent data to generate the second output audio data without departingfrom the disclosure. The device 110 may then output (848) audiocorresponding to the second output audio data.

While FIGS. 8A-8C illustrate an example in which both the device 110 andthe remote system 120 perform speech processing, the disclosure is notlimited thereto and in some examples the device 110 may detectsystem-directed speech and perform local speech processing on the audiodata without departing from the disclosure.

FIGS. 9A-9B are signal flow diagrams illustrating the processingperformed when a device detects system-directed speech represented ininput audio data and performs local speech processing on the input audiodata according to embodiments of the present disclosure. As illustratedin FIG. 9A, the device 110 may receive (902) first input audiocorresponding to an utterance with a wake command (e.g., determine thata wakeword is represented in the first input audio), may generate (904)first input audio data corresponding to the first input audio, mayperform (906) speech processing on the first input audio data todetermine a first command, and may determine (908) first contentresponsive to the first command.

The device 110 may optionally send (910) a request for the first contentto the skill server(s) 125. The skill server(s) 125 may determine (911)first content data corresponding to the first content and the device 110may receive (912) the first content data from the skill server(s) 125.Additionally or alternatively, the remote system 120 may determine thefirst content data without departing from the disclosure. Using thefirst content data, the device 110 may generate (914) first output audiodata and may output (916) audio corresponding to the first output audiodata.

As illustrated in FIG. 9B, while the device 110 is outputting the audiocorresponding to the first output audio data in step 916, the device 110may detect (918) second input audio, may generate (920) second inputaudio data corresponding to the second input audio, may perform (922)VAD processing on the second input audio data to detect speech, mayperform (924) ASR processing on the second input audio data to generateASR data, may determine (926) that the speech represented in the secondinput audio data is system-directed speech (e.g., device-directed speechor device-directed speech event), and may perform (928) NLU processingusing the ASR results to determine a second command.

The device 110 may determine (930) second content responsive to thesecond command and may optionally send (932) a request for the secondcontent to the skill server(s) 125. The skill server(s) 125 maydetermine (933) second content data corresponding to the second contentand the device 110 may receive (934) the second content data from theskill server(s) 125. Additionally or alternatively, the device 110 maydetermine the second content data without departing from the disclosure.Using the second content data, the device 110 may generate (936) secondoutput audio data and may output (938) audio corresponding to the secondoutput audio data.

FIG. 10 illustrates an example of on-device interrupt architectureaccording to embodiments of the present disclosure. As illustrated inFIG. 10, on-device interrupt architecture 1000 (e.g., barge-in detector)may include an interrupt detector 1010 and a device directed classifier1020. The on-device interrupt architecture 1000 may detect adevice-directed speech event (e.g., system-directed speech event), whichmay be also be referred to as a barge-in event, and may cause speechprocessing to be performed on audio data corresponding to thedevice-directed speech event.

In some examples, the on-device interrupt architecture 1000 maycorrespond to the system directed speech detector 285 described abovewith regard to FIGS. 2A-5B without departing from the disclosure. Forexample, the device 110 and the remote system 120 may both include thesystem directed speech detector 285, with the system directed speechdetector 285 located on the device 110 including components illustratedwith regard to the on-device interrupt architecture 1000 withoutdeparting from the disclosure. However, the disclosure is not limitedthereto, and in other examples the system directed speech detector 285may only be included on the device 110, in the form of the on-deviceinterrupt architecture 1000, whereas the remote system 100 may notinclude the system directed speech detector 285 without departing fromthe disclosure. Additionally or alternatively, the system directedspeech detector 285 may be different from the on-device interruptarchitecture 1000, such that the remote system 120 may include thesystem directed speech detector 285 while the device 110 includes theon-device interrupt architecture 1000 without departing from thedisclosure.

The device directed classifier 1020 may receive ASR data (e.g.,contextual information, semantic information, and/or the like) from anASR component 250 located on the device 110. In some examples, the ASRcomponent may include an end-pointer component 1030 or the likeconfigured to determine an endpoint of an utterance (e.g., performend-point detection).

In the example illustrated in FIG. 10, the device 110 may generate anaudio waveform 1002 using the microphone(s) 114. In some examples, thedevice 110 may be generating output audio (e.g., text-to-speech (TTS)notifications) using the loudspeaker(s) 116 when the device 110generates the audio waveform 1002, although the disclosure is notlimited thereto.

In some examples, the audio waveform 1002 may represent speech from auser 5. Typically, a device is configured to detect a wakewordrepresented in the speech and process an utterance following thewakeword in order to perform a voice command. To improve a userexperience, the on-device interrupt architecture 1000 may enable thedevice 110 to detect device-directed speech and perform a voice commandeven when the speech does not represent the wakeword (e.g., wakewordlessspeech). Thus, the on-device interrupt architecture 1000 may detect aninterrupt event (e.g., barge-in event, wakewordless speech) and thendetermine whether the interrupt event corresponds to a device-directedspeech event (e.g., a voice command directed to the device 110, asopposed to just conversation or other environmental noise). If theon-device interrupt architecture 1000 determines that thedevice-directed speech event is present, the device 110 may cause speechprocessing to be performed on the utterance to determine a voicecommand, enabling the user 5 to interact with the device 110 naturallywithout explicitly saying the wakeword.

The interrupt detector 1010 may process a portion of the audio waveform1002 (e.g., 300 ms to 500 ms of audio data at a time) and determinewhether an interrupt event is detected. For example, the interruptdetector 1010 may detect that the audio waveform 1002 represents speechand may determine that the speech is directed at the device 110. Thus,the interrupt detector 1010 may be trained and optimized to detect auser's wakewordless device-directed interrupt speech.

In response to detecting the interrupt event, the device 110 may performone or more first actions. For example, the device 110 may attenuate theoutput audio (e.g., decrease from a first volume level to a secondvolume level), pause the output audio (e.g., stop generating oroutputting the output audio completely), display (e.g., enable) one ormore indicator lights (e.g., visual indicator(s)), ask a question (e.g.,“What was that?”), and/or perform other actions to indicate to the user5 that the device 110 is listening. Thus, instead of forcing the user 5to speak over the output audio, the device 110 may lower an outputvolume level of the output audio and capture an utterance (e.g.,potential voice command) generated by the user 5.

In some examples, the device 110 may pause the output audio byidentifying a natural transition within playback audio datacorresponding to the output audio. For example, the device 110 mayidentify a current position in the playback audio data, may identify anupcoming word boundary represented in the playback audio data after thecurrent position, and may pause the output audio based on the wordboundary. Thus, the device 110 may determine a first portion of theplayback audio data ending at the word boundary, may generate the outputaudio using the first portion of the playback audio data, and may stopgenerating the output audio after the first portion of the playbackaudio data (e.g., not generate the output audio using a second portionof the playback audio data).

The device 110 may identify the word boundary using multiple techniquesknown to one of skill in the art. In some examples, individual wordboundaries or other information may be indicated using tags or otherinformation embedded in the output audio data (e.g., ID3 tag). Forexample, the output audio data may include one or more tags that may beused to identify word boundaries or other boundaries represented in theoutput audio data without departing from the disclosure. In otherexamples, the device 110 may perform natural language processing on theoutput audio data to identify the upcoming word boundary usingtechniques known to one of skill in the art. Additionally oralternatively, the device 110 may identify the upcoming word boundary bydetecting a decrease in audio energy represented in the output audiodata without departing from the disclosure.

For ease of illustration, the following description may refer toattenuating the output audio and/or displaying one or more indicatorlights. For example, the device 110 may enable visual indicator(s) toindicate that the device 110 is listening and may disable the visualindicator(s) if an interrupt event is ignored. However, the disclosureis not limited thereto and the device 110 may perform any of theabovementioned actions (e.g., attenuate the output audio, pause theoutput audio, display indicator lights, ask a question, etc.) withoutdeparting from the disclosure.

To reduce latency and improve a user experience, the interrupt detector1010 may process a short portion and/or small quantity of the audiowaveform 1002 (e.g., short span of input speech signal) and determinewhether the interrupt event is present relatively quickly (e.g., within300 ms to 500 ms), enabling the device 110 to attenuate the output audioand/or perform other actions promptly. In some examples, the interruptdetector 1010 may prioritize latency over accuracy in order to improvethe user experience. For example, the interrupt detector 1010 mayprocess a shorter duration and/or smaller quantity of the audio waveform1002, use a lower threshold value to detect an interrupt event, and/orthe like in order to reduce an amount of latency associated with theinterrupt detector 1010 identifying that an interrupt event isoccurring. However, these parameters may vary without departing from thedisclosure, enabling the device 110 to control an amount of latencyand/or accuracy based on user preferences. Additionally oralternatively, the device 110 may modify these parameters over time,updating the interrupt detector 1010 to optimize the user experience.

After the interrupt event is detected, the device 110 may process theaudio waveform 1002 using the ASR component 250 and/or the end-pointercomponent 1030. The ASR component 250 may generate incomplete ASR data1032 (e.g., contextual information, semantic information, and/or thelike) while processing portions of the audio waveform 1002 and maygenerate complete ASR data 1034 (e.g., contextual information, semanticinformation, and/or the like) corresponding to the entire utterance. Theend-pointer component 1030 may be configured to determine an endpoint ofan utterance and may determine the endpoint using techniques known toone of skill in the art without departing from the disclosure. WhileFIG. 10 illustrates the end-point component 1030 as part of the ASRcomponent 250, the disclosure is not limited thereto and the end-pointcomponent 1030 may be separate from the ASR component 250 withoutdeparting from the disclosure.

Prior to the device 110 identifying the endpoint of the utterance, insome examples the device directed classifier 1020 may process the audiowaveform 1002 and/or the ASR data 1032 (e.g., 1032 a, 1032 b, 1032 c,etc.) and determine a confidence level indicating a likelihood that theutterance corresponds to a device-directed speech event. Thus, thedevice directed classifier 1020 may process the incomplete audiowaveform 1002 and/or the incomplete ASR data 1032 and continuouslycalculate the confidence level prior to the device 110 detecting theendpoint of the utterance. If the confidence level falls below a firstthreshold value, the device directed classifier 1020 may reject theinterrupt event as not corresponding to a device-directed speech eventand perform one or more second actions. For example, the device 110 mayincrease the output volume level of the output audio (e.g., increasefrom the second volume level to the first volume level), may stopdisplaying (e.g., disable) the one or more indicator lights (e.g.,visual indicator(s)), and/or perform other actions to stop indicatingthat the device 110 is listening.

If the confidence level stays above the first threshold value and theend-pointer component 1030 detects the endpoint of the utterance, thedevice directed classifier 1020 may process the entire utterance (e.g.,portion of audio data or audio waveform 1002 representing the utterance)and/or the complete ASR data 1034 to determine whether a device-directedspeech event is present. In some examples, the device directedclassifier 1020 may detect the device-directed speech event by updatingthe previously calculate confidence level until the endpoint of theutterance. Thus, the device directed classifier 1020 may build off ofthe previous results to determine the confidence level for theutterance. However, the disclosure is not limited thereto, and in otherexamples the device directed classifier 1020 may process the entireutterance separately without departing from the disclosure. For example,the 10ASR component 250 may generate the complete ASR data 1034 (e.g.,contextual information, semantic information, and/or the like) byprocessing the entire utterance and then the device directed classifier1020 may determine the overall confidence level using the complete ASRdata 1034.

In some examples, the device directed classifier 1020 may determine anoverall confidence level for the utterance and determine whether theoverall confidence level satisfies a condition. For example, the devicedirected classifier 1020 may determine that the overall confidence levelis greater than a second threshold value, although the disclosure is notlimited thereto. When the overall confidence level satisfies thecondition, the device directed classifier 1020 may accept the interruptevent by indicating that a device-directed speech event is detected(e.g., high likelihood that the speech corresponds to a voice command).When the overall confidence level does not satisfy the condition, thedevice directed classifier 1020 may reject the interrupt event byindicating that a device-directed speech event is not detected. Thus,the device directed classifier 1020 may reject the interrupt event basedon the confidence level being below the first threshold value and/or theoverall confidence level being below the second threshold value,although the disclosure is not limited thereto.

As described above, if the device-directed classifier 1020 determinesthat the device-directed speech event is not present (e.g., theinterrupt event is rejected), the device 110 may perform one or moresecond actions. For example, the device 110 may increase the outputvolume level of the output audio (e.g., increase from the second volumelevel to the first volume level), may stop displaying (e.g., disable)the one or more indicator lights (e.g., visual indicator(s)), and/orperform other actions to stop indicating that the device 110 islistening. Thus, the device 110 continues whatever action it waspreviously performing (e.g., generating output audio) and ignores theutterance. If the device-directed classifier 1020 determines that thedevice-directed speech event is present (e.g., the interrupt event isaccepted, indicating that a voice command is detected), the device 110may cause speech processing to be performed on the audio data todetermine a voice command. For example, the device 110 may performspeech processing on the audio data locally and/or send the audio datarepresenting the audio waveform 1002 to the remote system 120 forfurther processing. Thus, the device-directed classifier 1020 determineswhether to execute the speech processing pipeline based on theutterance.

In contrast to constantly streaming audio data to the remote system 120during and/or after outputting audio responsive to a voice command,detecting the device-directed speech event enables the system 100 toonly process a portion of audio data representing device-directedspeech. This reduces a processing consumption imposed on the system 100while also improving privacy protection for a user 5 of the device 110.For example, as the system 100 only processes the portion of the audiodata directed to the device/system, the system 100 ignores speech thatis not directed to the device/system. Additionally or alternatively, thesystem 100 may be configured to train the on-device interruptarchitecture 1000 in real-time, without persistently storing anyinformation about an interaction. Thus, the device 110 may be configuredto learn and/or train the on-device interrupt architecture 1000 withoutstoring audio data, ASR data, and/or other data associated with aparticular interaction.

The interrupt detector 1010 and/or the device directed classifier 1020may determine whether device-directed speech is detected using at leastone classifier. For example, the classifier may consider a variety ofinformation, including a volume level of the speech (e.g., whether thespeech is louder or quieter than normal speech), speaker identification(e.g., identification data) corresponding to the speech, which may bedetermined using voice recognition, image data, and/or other techniquesknown to one of skill in the art, emotion detection (e.g., emotion data)corresponding to the speech (e.g., whether the speech is animated orquiet, for example), a length of time between when the output audiobegins and when the speech is detected, and/or the like withoutdeparting from the disclosure. The classifier may process the inputinformation and generate model output data, which may indicate alikelihood that the speech is directed to the device. If the modeloutput data satisfies a condition, the device 110 may determine that thespeech is directed to the device 110. For example, the model output datamay indicate a likelihood that is greater than a threshold value,although the disclosure is not limited thereto.

The device 110 may be located within an environment to provide variouscapabilities to a user 5, when the user 5 is also in the environment.The environment in which the device 110 is located may be a home orother premises, an automobile, or any similar environment. Such anenvironment may include other devices including additional speechinterface devices and/or second devices (e.g., Internet of Things (IoT)devices and/or smart home devices like thermostats, lights,refrigerators, ovens, etc.) that may be controllable by speech interfacedevices, such as the device 110. When acting as a hub, the device 110may be configured to connect a plurality of devices in an environmentand control communications among them, thereby serving as a place ofconvergence where data arrives from one or more devices, and from whichdata is sent to one or more devices.

In general, the device 110 may be capable of capturing utterances withmicrophone(s) 114, and responding in various ways, such as by outputtingcontent (e.g., audio) via an output device(s), which may beloudspeaker(s) 116, a display(s), or any other suitable output device.In addition, the device 110 may be configured to respond to user speechby controlling second devices that are collocated in the environmentwith the device 110, such as by sending a command to a second device viaa communications interface (e.g., a short range radio), the commandinstructing an operation to be performed at the second device (e.g., toturn on a light in the environment).

Under normal conditions, the device 110 may operate in conjunction withand/or under the control of a remote system 120, which may be a remote,network-based or network-accessible control system. The remote system120 may, in some instances be part of a network-accessible computingplatform that is maintained and accessible via network(s) 199.Network-accessible computing platforms such as this may be referred tousing terms such as “on-demand computing”, “software as a service(SaaS)”, “platform computing”, “network-accessible platform”, “cloudservices”, “data centers”, and so forth. The remote system 120 may beconfigured to provide particular functionality to large numbers of local(e.g., in-home, in-car, etc.) devices of different users.

In some embodiments, the remote system 120 may be configured to receiveaudio data from the device 110, to recognize speech corresponding to anutterance in the received audio data using a speech processing component240 (which may be referred to as a remote speech processing system), andto perform functions in response to the recognized speech. In someembodiments, these functions involve sending directives (e.g.,commands), from the remote system 120 to the device 110 to cause thedevice 110 to perform an action, such as output an audible response tothe utterance via loudspeaker(s) 116, and/or control second devices inthe environment by sending a control command via the communicationsinterface. Thus, under normal conditions, when the device 110 is able tocommunicate with the remote system 120 over the network(s) 199, some orall of the functions capable of being performed by the remote system 120may be performed by sending directive(s) over the network(s) 199 to thedevice 110, which, in turn, may process the directive(s) and performcorresponding action(s). For example, the remote system 120, using aremote directive that is included in response data (e.g., directivedata), may instruct the device 110 to output an audible response (e.g.,using text-to-speech (TTS)) to a user's 5 question via a loudspeaker(s)116 of the device 110, to output content (e.g., music) via theloudspeaker(s) 116 of the device 110, to display content on a display ofthe device 110, and/or to send a directive to a nearby device (e.g.,directive to turn on a light). It is to be appreciated that the remotesystem 120 may be configured to provide other functions in addition tothose discussed herein, such as, without limitation, providingstep-by-step directions for navigating from an origin to a destinationlocation, conducting an electronic commerce transaction on behalf of theuser 5 as part of a shopping function, establishing a communicationsession between the user 5 and another user, and so on.

FIG. 11 illustrates an example of wakewordless interrupt according toembodiments of the present disclosure. As illustrated in FIG. 11, theuser 5 may input a first voice command requesting that the device 110play music. For example, the device 110 may capture first audio input1110 (e.g., “Alexa, play the song ‘Yellow Bird.’”) corresponding to afirst utterance. Whether the first utterance is captured by themicrophone(s) 114 of the device 110 or captured by a remote microphonein the environment, first audio data representing the first utterance isultimately received by the device 110. The device 110 may recognize thatthe first audio data includes a representation of the wakeword (e.g.,“Alexa”) and may send the first audio data to the remote system 120 forprocessing.

The remote system 120 may process the audio data using a speechprocessing component 240, which is discussed above with regard to FIG.2, to generate NLU data and/or corresponding directive data. Forexample, the NLU data may correspond to intent data and/or slot datathat represent an intent associated with the first utterance, and thedirective data may include a directive that corresponds to the intent.In a conventional system, the remote system 120 may use the NLU datalocally to determine the directive data and may only send the directivedata to the device 110.

In the example illustrated in FIG. 11, the remote system 120 may processthe first audio data and determine that the first voice commandcorresponds to a request to play “Yellow Bird” by Arthur Lyman. Toprocess this request, the remote system 120 may perform text-to-speech(TTS) processing to generate output audio data representing anotification to the user 5. In addition, the remote system 120 maygenerate directive data commanding the device 110 to stream the song“Yellow Bird” by Arthur Lyman. The remote system 120 may then send theoutput audio data and the directive data to the device 110. In responseto receiving the output audio data and the directive data, the device110 may generate audio output 1120 (e.g. “Playing ‘Yellow Bird by ArthurLyman.”) and begin streaming the selected song.

In the example illustrated in FIG. 11, however, the user 5 was actuallyrequesting a different song than the one selected by the remote system120. Thus, while the device 110 is generating the audio output 1120, theuser 5 may input a second voice command requesting that the device 110play a different version of ‘Yellow Bird.’ For example, the device 110may capture second audio input 1130 (e.g., “No, play ‘Yellow Bird’ by‘Pretty Lights.’”) corresponding to a second utterance that does notinclude the wakeword. Whether the second utterance is captured by themicrophone(s) 114 of the device 110 or captured by a remote microphonein the environment, second audio data representing the second utteranceis ultimately received by the device 110. Even though the second audiodata does not include a representation of the wakeword, the device 110may detect an interrupt event (e.g., voice command) and process thesecond audio data using the on-device interrupt architecture 1000, asdescribed above. For example, the device directed classifier 1020 maydetermine that the interrupt event corresponds to a device-directedspeech event and may send the second audio data to the remote system 120for further processing, resulting in the device 110 playing the song“Yellow Bird” by the artist “Pretty Lights,” as requested by the user 5.

In the example illustrated in FIG. 11, the second audio input 1130 isreceived while the device 110 is generating the audio output 1120,although the disclosure is not limited thereto. Upon detecting theinterrupt event, the device 110 may perform one or more first actions toindicate that the device 110 is listening, such as attenuating the audiooutput 1120, displaying an indicator light, and/or the like, which isillustrated in FIG. 11 as the audio output 1120 being cut off before theend of the sentence.

While not illustrated in FIG. 11, if the device 110 determined that thesecond audio input 1130 did not correspond to a device-directed speechevent, the device 110 may perform one or more second actions to indicatethat the device 110 is no longer listening. For example, if the secondaudio input 1130 corresponded to the utterance “I love the song YellowBird” instead of a voice command, the device 110 may determine that thisinterrupt event does not correspond to a device-directed speech event(e.g., speech is detected, but it does not correspond to a voicecommand) and may choose to ignore the second utterance. Thus, the device110 may continue generating the audio output 1120 at the first volumelevel without sending the second audio data to the remote system 120.

FIGS. 12A-12D illustrate examples of different ways that the interruptarchitecture may process an utterance according to embodiments of thepresent disclosure. As illustrated in FIG. 12A, during normal processing1210 the device 110 may begin (1212) outputting audio, the environment1200 may generate (1214) an audible noise, the device 110 may determine(1216) that speech is not detected and finish (1218) outputting theaudio. For example, the device 110 may generate audio data and determinethat the audio data only represents environmental noise or othernon-speech sounds, resulting in the device 110 generating the outputaudio without interruption or attenuation.

In contrast, FIG. 12B illustrates an example in which an interrupt eventis detected and then rejected. As illustrated in FIG. 12B, wheninterrupt rejected 1220 occurs the device 110 may begin (1222)outputting audio, the environment 1200 may generate (1224) speech, andthe device 110 may detect (1226) the speech (e.g., device-directedspeech) and modify (1228) output of the output audio. For example, thedevice 110 may pause the output audio, reduce a volume level of theoutput audio (e.g., from a first volume level to a second volume level),and/or perform other actions. Thus, the device 110 may determine that aninterrupt event is present based on detecting the speech. However, thedevice 110 may reject (1230) the interrupt event and finish (1232)outputting the audio (e.g., un-pause the output audio, increase from thesecond volume level to the first volume level, and/or perform otheractions). For example, the device directed classifier 1020 may process aportion of the speech to determine a confidence level that the speechcorresponds to a device-directed speech event. If the device directedclassifier 1020 determines that the confidence level is below a firstthreshold value, the device directed classifier 1020 may reject theinterrupt event and continue normal processing. This may occur when thespeech corresponds to playback speech generated by another device (e.g.,dialog included in a television broadcast, remote speech included in anaudio broadcast, remote speech output during a communication session,and/or the like), non-device-directed speech generated by the user 5(e.g., conversation not directed at the device 110), and/or the likewithout departing from the disclosure.

While FIG. 12B illustrates an example in which the interrupt event isrejected prior to the end of an utterance, FIG. 12C illustrates anexample in which the interrupt event is rejected based on an entireutterance. As illustrated in FIG. 12C, when interrupt rejected 1230occurs the device 110 may begin (1242) outputting audio, the environment1200 may generate (1244) speech, and the device 110 may detect (1246)the speech (e.g., device-directed speech) and modify (1248) output ofthe output audio. For example, the device 110 may pause the outputaudio, reduce a volume level of the output audio (e.g., from a firstvolume level to a second volume level), and/or perform other actions.Thus, the device 110 may determine that an interrupt event is presentbased on detecting the speech. However, the device 110 may determine(1250) an end of the utterance, may reject (1252) the utterance (e.g.,reject the interrupt event), and may finish (1254) outputting the audio(e.g., un-pause the output audio, increase from the second volume levelto the first volume level, and/or perform other actions). For example,the device directed classifier 1020 may process the entire utterance todetermine an overall confidence level that the utterance corresponds toa device-directed speech event. If the device directed classifier 1020determines that the overall confidence level is below a second thresholdvalue, the device directed classifier 1020 may reject the interruptevent and continue normal processing. This may occur when the utterancecorresponds to playback speech generated by another device (e.g., dialogincluded in a television broadcast, remote speech included in an audiobroadcast, remote speech output during a communication session, and/orthe like), non-device-directed speech generated by the user 5 (e.g.,conversation not directed at the device 110), and/or the like withoutdeparting from the disclosure.

Finally, FIG. 12D illustrates an example of accepting the interruptevent and processing a voice command represented by wakewordlessdevice-directed speech. As illustrated in FIG. 12D, when interruptaccepted 1260 occurs the device 110 may begin (1262) outputting audio,the environment 1200 may generate (1264) speech, and the device 110 maydetect (1266) the speech (e.g., device-directed speech) and modify(1268) output of the output audio. For example, the device 110 may pausethe output audio, reduce a volume level of the output audio (e.g., froma first volume level to a second volume level), and/or perform otheractions. Thus, the device 110 may determine that an interrupt event ispresent based on detecting the speech.

In this example, however, the device 110 may determine (1270) an end ofthe utterance, may detect (1272) a device-directed speech event (e.g.,accept the interrupt event), may stop (1274) outputting the audio (e.g.,cause the output audio to stop), and may cause (1276) speech processingto be performed. For example, the device 110 may send input audio datacorresponding to the utterance to the remote system 120 for speechprocessing. Additionally or alternatively, the device 110 may performlocal speech processing on the input audio data without departing fromthe disclosure. In some examples, the device directed classifier 1020may process the entire utterance to determine an overall confidencelevel that the utterance corresponds to a device-directed speech event.If the device directed classifier 1020 determines that the overallconfidence level is above the second threshold value, the devicedirected classifier 1020 may accept the interrupt event and send theutterance to the remote system 120.

FIG. 13 illustrates a decision table and training data associated withinterrupt architecture according to embodiments of the presentdisclosure. Examples of potential outputs and corresponding actions toperform are illustrated in decision table 1300. For example, theinterrupt detector output may indicate that speech is not detected orthat speech is detected. If the interrupt detector output indicates thatspeech is not detected (e.g., interrupt event not present), then theaction to perform is to continue generating output audio at a normalvolume level. However, if the interrupt detector output indicates thatspeech is detected (e.g., interrupt event is present), then the actionto perform is to indicate that the device 110 is listening by performingat least one of lower the volume level of the output audio from a firstvolume level to a second volume level, display indicator light(s),and/or the like. Thus, the interrupt detector output results in thedevice 110 performing one or more actions to indicate to the user 5 thatthe device 110 is listening.

When the interrupt detector output indicates that speech is notdetected, the device directed classifier 1020 does not process the audiodata and nothing else occurs, indicated in the decision table 1300 asnot applicable (e.g., N/A). When the interrupt detector output indicatesthat speech is detected, however, the device directed classifier 1020can perform one of three different actions. First, the device directedclassifier 1020 can reject the interrupt event before the end of theutterance, as described in greater detail above. For example, the devicedirected classifier 1020 can process portions of the audio data,determine that a confidence level is below a first threshold value, andreject the interrupt event. Second, the device directed classifier 1020can process the entire utterance and determine to reject the interruptevent. For example, the device directed classifier 1020 can receive anindication of an endpoint of the utterance from the ASR component andmay process the entire utterance to determine an overall confidencelevel that the utterance corresponds to a device-directed speech event.If the overall confidence level is below a second threshold value, thedevice directed classifier 1020 can reject the interrupt event at thispoint in time. Regardless of whether the device directed classifier 1020rejects the interrupt event prior to the end of the utterance or basedon the complete utterance, the action to perform is to continuegenerating output audio at a normal volume. For example, the device 110may increase the output audio from the second volume level to the firstvolume level and/or turn off any indicator light(s) previouslydisplayed.

Third, the device directed classifier 1020 can process the entireutterance and determine to accept the interrupt event. For example, thedevice directed classifier 1020 may determine that the overallconfidence level is above the second threshold value, indicating thatthe interrupt event corresponds to a device-directed speech event. Whenthis occurs, the device 110 may stop generating the output audio (e.g.,cause the output audio to stop) and may send first audio datarepresenting the utterance to the remote system 120 for furtherprocessing. For example, the first audio data may correspond to a voicecommand and the remote system 120 may interpret the voice command andsend directive data to the device 110 and/or other devices withoutdeparting from the disclosure.

To improve the interrupt detector 1010, the device 110 may generatetraining data 1310 based on the device directed classifier output andperform a training process to update the interrupt detector 1010. Asillustrated in FIG. 13, the device directed classifier 1020 may send thetraining data 1310 to the interrupt detector 1010. For example, thedecision table 1300 indicates that the device 110 may generate firsttraining data (e.g., NOT-INTERRUPT) when the interrupt event is rejectedand/or second training data (e.g., INTERRUPT) when the interrupt eventis accepted.

As the device directed classifier 1020 processes the full speech segment(e.g., entire utterance) and ASR hypothesis, along with additionalsemantic level information, the device-directed classifier output canachieve a lower false accept (FA) rate than the interrupt detectoroutput. Thus, the device 110 may use the device directed classifieroutput as ground truth to enable on-device federated learning to improvethe interrupt detector 1010. Specifically, a rejected interrupt event(e.g., falsely accepted speech segment) may be used to generate thefirst training data (e.g., NOT-INTERRUPT) and improve the interruptdetector 1010 in a privacy-preserving federated learning framework. Forexample, gradients for selected rejected interrupt events may becalculated on-device, while gradients from many devices may beaggregated by the remote system 120 and/or a remote database. The remotesystem 120 may apply these gradients to the baseline shared interruptdetector model to generate an updated interrupt detector model and theupdated interrupt detector model may be sent to the devices 110.

Similarly, the device 110 may use an accepted interrupt event (e.g.,device-directed speech segment) to generate the second training data(e.g., INTERRUPT). For example, an interrupt event that was not detected(e.g., falsely rejected speech segment) followed by an acceptedinterrupt event may be used in a federated learning framework to improvean interrupt false reject (FR) rate. Specifically, the interruptdetector 1010 may identify near-miss interrupt events (e.g., portions ofaudio data that were just below a threshold value and therefore notselected as an interrupt event) that were followed by accepted interruptevents, treat the near-miss interrupt events as false rejections, anduse the near-miss interrupt events as positive examples to improve theinterrupt detector 1010.

In some examples, the first training data and the second training datamay include the interrupt detector output, the device directedclassifier output, the first audio data, contextual information (e.g.,information about the first audio data, data generated at the time thatthe first audio data was captured, second audio data generated for aduration of time prior to the first audio data, and/or the like), and/orother information without departing from the disclosure. Using thetraining data 1310, the interrupt detector 1010 may perform the trainingprocess to improve future results. For example, the interrupt detector1010 may include an interrupt classifier, interrupt detection model oralgorithm, and/or the like and the device 110 may update the interruptclassifier/model using the training data 1310. By performing thetraining process, the interrupt detector 1010 may achieve a low falseaccept (FA) rate (e.g., false positive) while only processing a shortspeech segment (e.g., short portion of the utterance), enabling thedevice 110 to decrease a latency associated with the interrupt detector1010 detecting an interrupt event.

In addition to the training data 1310 illustrated in FIG. 13, theinterrupt detector 1010 may perform training based on various inputs,including user feedback (e.g., direct feedback and/or feedback inferredbased on subsequent responses), remote feedback from the remote system120, and/or the like. As used herein, on-device training corresponds toany modification of the interrupt detector 1010 performed by the device110, whether based on the training data 1310, user feedback, remotefeedback, or any other input to the device 110. For example, the device110 may modify the interrupt detector 1010 (e.g., interrupt detectionmodel or algorithm) itself, may modify weights associated with theinterrupt detector 1010, and/or the like based on a feedback process.

In contrast to constantly streaming audio data to the remote system 120during and/or after outputting audio responsive to a voice command,detecting the device-directed speech event enables the system 100 toonly process a portion of audio data representing device-directedspeech. This reduces a processing consumption imposed on the system 100while also improving privacy protection for a user 5 of the device 110.For example, as the system 100 only processes the portion of the audiodata directed to the device/system, the system 100 ignores speech thatis not directed to the device/system.

Additionally or alternatively, the system 100 may be configured to trainthe on-device interrupt architecture 1000 in real-time, withoutpersistently storing any information about an interaction. Thus, thedevice 110 may be configured to learn and/or train the on-deviceinterrupt architecture 1000 without storing audio data, ASR data, and/orother data associated with a particular interaction.

FIG. 14 is a flowchart conceptually illustrating an example method forperforming interrupt processing according to embodiments of the presentdisclosure. As illustrated in FIG. 14, the device 110 may receive (1410)microphone audio data, may determine (1412) that an interrupt event isdetected, and may perform (1414) action(s) to indicate that the device110 is listening. For example, the device 110 may reduce a volume levelof output audio from a first volume level to a second volume level, maydisplay indicator light(s), and/or the like.

The device 110 may determine (1416) a preliminary confidence level thata device-directed speech event is detected and may determine (1418)whether the preliminary confidence level is below a first thresholdvalue. If the preliminary confidence level is below the first thresholdvalue, the device 110 may skip to step 1424. If the preliminaryconfidence level is above the first threshold value, the device 110 maydetermine (1420) whether the device 110 detects an end of the utterance(e.g., endpoint). If the endpoint is not detected, the device 110 mayloop to step 1416 and repeat steps 1416-1420 until the endpoint isdetected.

If the endpoint is detected in step 1420, the device 110 may determine(1422) whether a device-directed speech event is detected. If adevice-directed speech event is not detected, the device 110 may rejectthe interrupt event, may continue (1424) generating the output audio andmay perform (1426) action(s) to stop indicating that the device 110 islistening. For example, the device 110 may increase the volume level ofthe output audio from the second volume level to the first volume levelwhile turning off (e.g., disabling) any indicator light(s) that wereturned on in step 1414.

If a device-directed speech event is detected in step 1422, the device110 may stop (1428) generating the output audio and may perform (1430)speech processing on the microphone audio data (e.g., a portion of themicrophone audio data corresponding to the utterance). For example, thedevice 110 may stop playback of a notification or other text-to-speech,may send the microphone audio data to the remote system 120, and mayperform one or more actions received from the remote system in responseto the microphone audio data. Additionally or alternatively, the device110 may stop playback of the notification or other text-to-speech, mayperform local speech processing on the microphone audio data, and mayperform one or more actions determined based on the local speechprocessing without departing from the disclosure.

FIG. 15 is a flowchart conceptually illustrating an example method fortraining an interrupt detector according to embodiments of the presentdisclosure. As illustrated in FIG. 15, the device 110 may determine(1510) that an interrupt event is detected and may determine whether(1512) device-directed speech is detected. If device-directed speech isdetected, the device 110 may determine (1514) that a device-directedspeech event is detected (e.g., accepted interrupt event) and generate(1516) positive training data based on the device-directed speech event.If device-directed speech is not detected, the device 110 may determine(1518) that a device-directed speech event is not detected (e.g.,rejected interrupt event) and may generate (1520) negative trainingdata. At some point in time after generating the positive training dataand/or the negative training data, the device 110 may train (1522) theinterrupt detector 1010, as described in greater detail above.

FIG. 16 illustrates example implementations for interrupt architectureaccording to embodiments of the present disclosure. As illustrated inFIG. 16, the on-device interrupt architecture 1000 may be used in one ofat least three implementations. In a first implementation, illustratedin FIG. 16 as interrupt scenario 1610, the device 110 may generateoutput audio 1612 and may detect an interrupt event 1614 whilegenerating the output audio 1612. The interrupt scenario 1610 isdescribed in greater detail above, and corresponds to an example inwhich the device 110 may reduce a volume level of the output audio 1612in response to the interrupt event 1614.

In a second implementation, illustrated in FIG. 16 as follow-up scenario1620, the device 110 may generate output audio 1622 and may detect aninterrupt event 1624 within a duration of time after generating theoutput audio 1622. For example, the device 110 may stop generating theoutput audio 1622 but may listen for device-directed speech for theduration of time. If the device 110 detects the interrupt event 1624within the duration of time, the device 110 may determine whether theinterrupt event corresponds to a device-directed speech event and mayprocess a voice command without detecting the wakeword. As the device110 is not generating the output audio 1622 when the interrupt event1624 is detected, the device 110 may not reduce a volume level of theoutput audio 1622 or perform other actions described above with regardto the interrupt scenario 1610.

In a third implementation, illustrated in FIG. 16 as wakewordlessinterrupt scenario 1630, the device 110 may not generate output audio1632 and may detect an interrupt event 1634 at any point in time. Forexample, the device 110 may listen for device-directed speech for anindefinite duration of time without regard to the output audio 1632,enabling the device 110 to process a voice command at any point in timewithout detecting the wakeword. As a result, the device 110 may beconfigured to identify the voice command by detecting a device-directedspeech event instead of detecting a representation of the wakeword.

FIG. 17 illustrate example implementations for wakewordless interruptarchitecture according to embodiments of the present disclosure. Asillustrated in FIG. 17, the wakewordless interrupt architecture may beincluded in a speech-enabled device 110 a as illustrated in deviceimplementation 1710, in a doorbell 110 b as illustrated in doorbellimplementation 1720, in a vehicle 110 c as illustrated in automobileimplementation 1730, and/or the like without departing from thedisclosure. Thus, each of the devices 110 a-110 c may include on-deviceinterrupt architecture 1000 that may be used during an interruptscenario 1610, a follow-up scenario 1620, and/or a wakewordlessinterrupt scenario 1630 without departing from the disclosure.

In some examples, the device 110 may use the on-device interruptdetector 1000 or a similar component to ignore a wakeword represented inaudio data. For example, the device 110 may determine that a wakeword isrepresented in first audio data, may determine that the first audio datadoes not represent device-directed speech, and may determine to ignorethe wakeword because the first audio data does not representeddevice-directed speech.

While the above description refers to the device directed classifier1020 processing ASR data in addition to the audio data, the disclosureis not limited thereto. In some examples, the device directed classifier1020 may process additional audio data (e.g., previous 5-10 seconds ofaudio data prior to the interrupt detector 1010 detecting an interruptevent), additional ASR data (e.g., second ASR data corresponding to theadditional audio data), and/or other information (e.g., NLU data, aprevious command, etc.) without departing from the disclosure. Forexample, the device 110 may process data corresponding to a previousinteraction (e.g., previous voice command) as part of detecting aninterrupt event and/or device-directed speech event.

Additionally or alternatively, the interrupt detector 1010 may processthe additional information described above without departing from thedisclosure.

In some examples, the device 110 may perform speaker identification todetect the interrupt event and/or the device-directed speech event. Forexample, the device 110 may detect a first command (e.g., first audiodata representing a first command) generated by a first user associatedwith first identification data and may output audio responsive to thefirst command. If the device 110 detects speech (e.g., second audio datarepresenting a second command) while outputting the audio, the device110 may confirm whether the speech corresponds to the first userassociated with the first identification data as part of detecting theinterrupt event and/or the device-directed speech event. For example, ifthe speech corresponds to the first user, the device 110 may detect theinterrupt event and/or the device-directed speech event, whereas if thespeech corresponds to a second user different from the first user (e.g.,not associated with the first identification data), the device 110 mayignore the interrupt event and/or the device-directed speech event.Thus, the device 110 may optionally only detect device-directed speechevents when the speech is generated by the same user as a previous voicecommand.

In some examples, the device 110 may perform speaker identification todetermine the first identification data, as described above. However,the disclosure is not limited thereto, and the device 110 may use voicerecognition on the second audio data, computer processing on secondimage data corresponding to the second audio data, and/or othertechniques known to one of skill in the art to determine the firstidentification data. Additionally or alternatively, the device 110 maydetermine that the first command (e.g., previous command) corresponds tothe first identification data (e.g., first user) by performing speakeridentification and/or voice recognition on the first audio datarepresenting the first command, performing speaker identification and/orvoice recognition on a portion of the first audio data representing thewakeword (e.g., determining that the second command corresponds to thewakeword preceding the first command), performing computer processing onfirst image data corresponding to the first audio data, using the otherdata 581/591 indicating identification data associated with the previousutterance, and/or the like without departing from the disclosure. If thedevice 110 determines that the first command and the second command bothcorrespond to the first identification data, the interrupt detector 1010and/or the device directed classifier 1020 may increase a weight of themodel output data (e.g., more heavily weight speech if it came from thefirst user that generated the first command).

While some of the examples described above rely on determining anendpoint of an utterance to detect a device-directed speech event, thedisclosure is not limited thereto. For example, in some examples thedevice 110 may detect speech and may identify an endpoint after speechis not detected for a duration of time (e.g., 500 ms, although thedisclosure is not limited thereto). Once the endpoint is detected, thedevice directed classifier 1020 may receive an indication of theendpoint and may process the entire utterance, as described in greaterdetail above. Thus, the device directed classifier 1020 may be triggeredby the device 110 detecting the endpoint of the utterance.

In other examples, however, the device 110 may detect speech and triggerthe device directed classifier 1020 after a specified duration of timeregardless of whether speech is detected. For example, the device 110may detect speech and may trigger the device directed classifier 1020after a duration of time (e.g., 100-500 ms) from when the speech wasfirst detected, without regard to whether speech is represented in theaudio data (e.g., device 110 does not wait for silence and/or detectingan endpoint). Thus, the device 110 may periodically process input audiodata using the device directed classifier 1020 without departing fromthe disclosure.

FIG. 18 is a block diagram conceptually illustrating a user device 110that may be used with the system. FIG. 19 is a block diagramconceptually illustrating example components of a remote device, such asremote server(s) 1920 included in the remote system 120, which mayassist with ASR processing, NLU processing, SLU processing and/orcommand processing. Multiple remote servers 1920 may be included in theremote system 120, such as one or more servers for performing ASR, oneor more remote servers 1920 for performing NLU, etc. In operation, eachof these devices (or groups of devices) may include computer-readableand computer-executable instructions that reside on the respectivedevice (110/1920), as will be discussed further below. The term “server”as used herein may refer to a traditional server as understood in aserver/client computing structure but may also refer to a number ofdifferent computing components that may assist with the operationsdiscussed herein. For example, a server may include one or more physicalcomputing components (such as a rack server) that are connected to otherdevices/components either physically and/or over a network and iscapable of performing computing operations. A server may also includeone or more virtual machines that emulates a computer system and is runon one or across multiple devices. A server may also include othercombinations of hardware, software, firmware, or the like to performoperations discussed herein. The server(s) may be configured to operateusing one or more of a client-server model, a computer bureau model,grid computing techniques, fog computing techniques, mainframetechniques, utility computing techniques, a peer-to-peer model, sandboxtechniques, or other computing techniques.

Each of these devices (110/1920) may include one or morecontrollers/processors (1804/1904), which may each include a centralprocessing unit (CPU) for processing data and computer-readableinstructions, and a memory (1806/1906) for storing data and instructionsof the respective device. The memories (1806/1906) may individuallyinclude volatile random access memory (RAM), non-volatile read onlymemory (ROM), non-volatile magnetoresistive memory (MRAM), and/or othertypes of memory. Each device (110/1920) may also include a data storagecomponent (1808/1908) for storing data andcontroller/processor-executable instructions. Each data storagecomponent (1808/1908) may individually include one or more non-volatilestorage types such as magnetic storage, optical storage, solid-statestorage, etc. Each device (110/1920) may also be connected to removableor external non-volatile memory and/or storage (such as a removablememory card, memory key drive, networked storage, etc.) throughrespective input/output device interfaces (1802/1902).

Computer instructions for operating each device (110/1920) and itsvarious components may be executed by the respective device'scontroller(s)/processor(s) (1804/1904), using the memory (1806/1906) astemporary “working” storage at runtime. A device's computer instructionsmay be stored in a non-transitory manner in non-volatile memory(1806/1906), storage (1808/1908), or an external device(s).Alternatively, some or all of the executable instructions may beembedded in hardware or firmware on the respective device in addition toor instead of software.

Each device (110/1920) includes input/output device interfaces(1802/1902). A variety of components may be connected through theinput/output device interfaces (1802/1902), as will be discussed furtherbelow. Additionally, each device (110/1920) may include an address/databus (1824/1924) for conveying data among components of the respectivedevice. Each component within a device (110/1920) may also be directlyconnected to other components in addition to (or instead of) beingconnected to other components across the bus (1824/1924).

Referring to FIG. 18, the device 110 may include input/output deviceinterfaces 1802 that connect to a variety of components such as an audiooutput component such as loudspeaker(s) 116, a speaker (notillustrated), a wired headset or a wireless headset (not illustrated),or other component capable of outputting audio. The device 110 may alsoinclude an audio capture component. The audio capture component may be,for example, one or more microphone(s) 114 or an array of microphones, awired headset or a wireless headset (not illustrated), etc. If an arrayof microphones is included, approximate distance to a sound's point oforigin may be determined by acoustic localization based on time andamplitude differences between sounds captured by different microphonesof the array. The device 110 may additionally include a display 1816 fordisplaying content and/or a camera 1818 for generating image data,although the disclosure is not limited thereto.

Via antenna(s) 1814, the input/output device interfaces 1802 may connectto one or more network(s) 199 via a wireless local area network (WLAN)(such as WiFi) radio, Bluetooth, and/or wireless network radio, such asa radio capable of communication with a wireless communication networksuch as a Long Term Evolution (LTE) network, WiMAX network, 3G network,4G network, 5G network, etc. A wired connection such as Ethernet mayalso be supported. Through the network(s) 199, the system 100 may bedistributed across a networked environment. The I/O device interface(1802/1902) may also include communication components that allow data tobe exchanged between devices such as different physical servers in acollection of servers or other components.

The components of the device(s) 110 and the remote system 120 mayinclude their own dedicated processors, memory, and/or storage.Alternatively, one or more of the components of the device(s) 110 andthe remote system 120 may utilize the I/O interfaces (1802/1902),processor(s) (1804/1904), memory (1806/1906), and/or storage (1808/1908)of the device(s) 110 and remote system 120, respectively. Thus, the ASRcomponent 250 may have its own I/O interface(s), processor(s), memory,and/or storage; the NLU component 260 may have its own I/O interface(s),processor(s), memory, and/or storage; and so forth for the variouscomponents discussed herein.

As noted above, multiple devices may be employed in a single system. Insuch a multi-device system, each of the devices may include differentcomponents for performing different aspects of the system's processing.The multiple devices may include overlapping components. The componentsof the device 110 and the remote system 120, as described herein, areexemplary, and may be located as a stand-alone device or may beincluded, in whole or in part, as a component of a larger device orsystem.

As illustrated in FIG. 20, multiple devices (110 a-110 g, 120, 125) maycontain components of the system and the devices may be connected over anetwork(s) 199. The network(s) 199 may include a local or privatenetwork or may include a wide network such as the Internet. Devices maybe connected to the network(s) 199 through either wired or wirelessconnections. For example, a speech-detection device 110 a, a smartphone110 b, a smart watch 110 c, a tablet computer 110 d, a vehicle 110 e, aspeech-detection and display device 110 f, and/or a smart TV 110 g maybe connected to the network(s) 199 through a wireless service provider,over a WiFi or cellular network connection, or the like. Other devicesare included as network-connected support devices, such as the remotesystem 120, skill server(s) 125, or others. The support devices mayconnect to the network(s) 199 through a wired connection or wirelessconnection. Networked devices may capture audio using one-or-morebuilt-in or connected microphones or other audio capture devices, withprocessing performed by ASR components, NLU components, or othercomponents of the same device or another device connected via thenetwork(s) 199, such as the ASR component 250, the NLU component 260,etc. of one or more remote servers 1920.

The concepts disclosed herein may be applied within a number ofdifferent devices and computer systems, including, for example,general-purpose computing systems, speech processing systems, anddistributed computing environments.

The above aspects of the present disclosure are meant to beillustrative. They were chosen to explain the principles and applicationof the disclosure and are not intended to be exhaustive or to limit thedisclosure. Many modifications and variations of the disclosed aspectsmay be apparent to those of skill in the art. Persons having ordinaryskill in the field of computers and speech processing should recognizethat components and process steps described herein may beinterchangeable with other components or steps, or combinations ofcomponents or steps, and still achieve the benefits and advantages ofthe present disclosure. Moreover, it should be apparent to one skilledin the art, that the disclosure may be practiced without some or all ofthe specific details and steps disclosed herein.

Aspects of the disclosed system may be implemented as a computer methodor as an article of manufacture such as a memory device ornon-transitory computer readable storage medium. The computer readablestorage medium may be readable by a computer and may compriseinstructions for causing a computer or other device to perform processesdescribed in the present disclosure. The computer readable storagemedium may be implemented by a volatile computer memory, non-volatilecomputer memory, hard drive, solid-state memory, flash drive, removabledisk, and/or other media. In addition, components of system may beimplemented as in firmware or hardware, such as an acoustic front end(AFE), which comprises, among other things, analog and/or digitalfilters (e.g., filters configured as firmware to a digital signalprocessor (DSP)).

Conditional language used herein, such as, among others, “can,” “could,”“might,” “may,” “e.g.,” and the like, unless specifically statedotherwise, or otherwise understood within the context as used, isgenerally intended to convey that certain embodiments include, whileother embodiments do not include, certain features, elements and/orsteps. Thus, such conditional language is not generally intended toimply that features, elements, and/or steps are in any way required forone or more embodiments or that one or more embodiments necessarilyinclude logic for deciding, with or without other input or prompting,whether these features, elements, and/or steps are included or are to beperformed in any particular embodiment. The terms “comprising,”“including,” “having,” and the like are synonymous and are usedinclusively, in an open-ended fashion, and do not exclude additionalelements, features, acts, operations, and so forth. Also, the term “or”is used in its inclusive sense (and not in its exclusive sense) so thatwhen used, for example, to connect a list of elements, the term “or”means one, some, or all of the elements in the list.

Disjunctive language such as the phrase “at least one of X, Y, Z,”unless specifically stated otherwise, is understood with the context asused in general to present that an item, term, etc., may be either X, Y,or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, suchdisjunctive language is not generally intended to, and should not, implythat certain embodiments require at least one of X, at least one of Y,or at least one of Z to each be present.

As used in this disclosure, the term “a” or “one” may include one ormore items unless specifically stated otherwise. Further, the phrase“based on” is intended to mean “based at least in part on” unlessspecifically stated otherwise.

What is claimed is:
 1. A computer-implemented method, the methodcomprising: receiving, at a microphone, first audio; generating firstinput audio data representing the first audio; processing the firstinput audio data using a wakeword detector of a device to determine thatthe first input audio data includes a representation of a wakeword;sending at least a portion of the first input audio data for speechprocessing; receiving first output audio data generated in response tothe first input audio data; generating, using the first output audiodata and a loudspeaker of the device, first output audio; receiving, atthe microphone, second audio; generating second input audio datarepresenting the second audio; processing the second input audio datausing a voice activity detector of the device to determine that firstspeech is represented in the second input audio data; processing thesecond input audio data using a first classifier of the device todetermine that the first speech is directed to the device, the firstclassifier configured to process a first quantity of audio data;detecting a first endpoint of the first speech represented in the secondinput audio data; determining, using the first endpoint, a portion ofthe second input audio data that represents the first speech; processingthe portion of the second input audio data using a second classifier todetermine that the first speech is directed to the device, the secondclassifier configured to process a second quantity of audio data that islarger than the first quantity; causing output of the first output audioto stop; and sending at least the portion of the second input audio datafor speech processing.
 2. The computer-implemented method of claim 1,further comprising: receiving second output audio data; generating,using the second output audio data and the loudspeaker, second outputaudio at a first volume level; receiving, at the microphone, thirdaudio; generating third input audio data representing the third audio;processing the third input audio data using the voice activity detectorto determine that second speech is represented in a portion of the thirdinput audio data; processing the third input audio data using the firstclassifier to determine that the second speech is directed to thedevice; enabling a visual indicator that indicates that the device islistening; processing the third input audio data using the secondclassifier to determine that the second speech is not directed to thedevice; and disabling the visual indicator.
 3. The computer-implementedmethod of claim 1, wherein causing the output of the first output audioto stop further comprises: determining a current position in the firstoutput audio data; identifying a word boundary represented in the firstoutput audio data after the current position, the word boundaryindicated by first information included within the first output audiodata; determining a first portion of the first output audio data endingat the word boundary; generating the first output audio using theloudspeaker and the first portion of the output audio data; and causingthe first output audio to stop after the first portion of the outputaudio data.
 4. The computer-implemented method of claim 1, whereinprocessing the second input audio data using the first classifierfurther comprises: determining a volume level of the second input audiodata; determining first identification data associated with the firstspeech; determining emotion data corresponding to the first speech;determining a length of time between generating the first output audioand receiving the second audio; determining, using the first classifier,first model output data using the volume level, the first identificationdata, the emotion data, and the length of time; and determining that thefirst model output data satisfies a condition.
 5. A computer-implementedmethod, comprising: generating first output audio using a loudspeakerassociated with a device; receiving first audio data; processing thefirst audio data using a first component of the device to determine thata first portion of the first audio data represents first speech that isdirected to the device; in response to determining that the first speechis represented in the first portion of the first audio data, performinga first action; determining that the first speech is represented in asecond portion of the first audio data that includes the first portionof the first audio data; processing the second portion of the firstaudio data using a second component of the device to determine that thefirst speech is directed to the device; and causing speech processing tobe performed on the second portion of the first audio data.
 6. Thecomputer-implemented method of claim 5, further comprising: generatingsecond output audio using the loudspeaker; receiving second audio data;processing the second audio data using the first component to determinethat speech is represented in a portion of the second audio data;performing the first action; processing the second audio data using thesecond component to determine a confidence value indicating a likelihoodthat the second audio data corresponds to a device-directed speechevent; determining that the confidence value satisfies a condition; andperforming a second action.
 7. The computer-implemented method of claim5, further comprising: generating second output audio using theloudspeaker; receiving second audio data; processing the second audiodata using the first component to determine that a first portion of thesecond audio data represents second speech that is directed to thedevice; performing the first action; determining that the second speechis represented in a second portion of the second audio data thatincludes the first portion of the second audio data; processing thesecond portion of the second audio data using the second component todetermine that the second speech is not directed to the device; andperforming a second action.
 8. The computer-implemented method of claim7, further comprising: generating training data corresponding to thesecond audio data, the training data indicating a rejected interruptevent; and training the first component using the training data.
 9. Thecomputer-implemented method of claim 5, further comprising: receivingoutput audio data; generating, using the loudspeaker and the outputaudio data, second output audio at a first volume level; receivingsecond audio data; processing the second audio data using the firstcomponent to determine that a portion of the second audio datarepresents second speech that is directed to the device; generating,using the loudspeaker and the output audio data, the second output audioat a second volume level that is lower than the first volume level;processing the second audio data using the second component to determinethat the second audio data does not correspond to a device-directedspeech event; and generating, using the loudspeaker and the output audiodata, the second output audio at the first volume level.
 10. Thecomputer-implemented method of claim 5, further comprising: generatingsecond output audio using a loudspeaker; receiving second audio data;processing the second audio data using the first component to determinethat a portion of the second audio data represents second speech that isdirected to the device; performing the first action, wherein performingthe first action enabling a visual indicator on the device; processingthe second audio data using the second component to determine that thesecond audio data does not correspond to a device-directed speech event;and disabling the visual indicator.
 11. The computer-implemented methodof claim 5, further comprising: processing the first audio data using avoice activity detector of the first component to determine that thespeech is represented in the first portion of the first audio data; andprocessing the first audio data using a classifier of the firstcomponent to determine that an interrupt event is represented in thefirst audio data.
 12. The computer-implemented method of claim 5,further comprising: detecting, by a speech processing component of thedevice, an endpoint of the first speech represented in the first audiodata; determining, by the speech processing component, semanticinformation associated with the first speech; and processing, using aclassifier of the second component, the second portion of the firstaudio data and the semantic information to determine that the firstspeech corresponds to a device-directed speech event.
 13. Thecomputer-implemented method of claim 5, further comprising: receivingsecond audio data; processing the second audio data using a wakeworddetector of the device to determine that the second audio data includesa representation of a wakeword; sending, by the device to the remotesystem, at least a portion of the second audio data; receiving, by thedevice and from the remote system, output audio data responsive to thesecond audio data; and generating the first output audio using theloudspeaker and the output audio data.
 14. The computer-implementedmethod of claim 5, comprising: determining a current position in outputaudio data, the output audio data corresponding to the first outputaudio; identifying a word boundary represented in the output audio dataafter the current position; determining a first portion of the outputaudio data ending at the word boundary; generating the first outputaudio using the loudspeaker and the first portion of the output audiodata; and causing the first output audio to be stopped after the firstportion of the output audio data.
 15. The computer-implemented method ofclaim 5, further comprising: receiving, prior to generating the firstoutput audio, second audio data; processing the second audio data usinga wakeword detector of the device to determine that the second audiodata includes a representation of a wakeword; causing speech processingto be performed on the second audio data; determining firstidentification data associated with second speech represented in thesecond audio data; and generating the first output audio using theloudspeaker and output audio data responsive to the second audio data,wherein processing the second portion of the first audio data furthercomprises: determining that the first speech corresponds to the firstidentification data.
 16. A system comprising: at least one processor;and memory including instructions operable to be executed by the atleast one processor to cause the system to: generate first output audiousing a loudspeaker associated with a device; receive first audio data;process the first audio data using a first component of the device todetermine that a first portion of the first audio data represents firstspeech that is directed to the device; in response to determining thatthe first speech is represented in the first portion of the first audiodata, perform a first action; determine that the first speech isrepresented in a second portion of the first audio data that includesthe first portion of the first audio data; process the second portion ofthe first audio data using a second component of the device to determinethat the first speech is directed to the device; and cause speechprocessing to be performed on the second portion of the first audiodata.
 17. The system of claim 16, wherein the memory further comprisesinstructions that, when executed by the at least one processor, furthercause the system to: generate second output audio using the loudspeaker;receive second audio data; process the second audio data using the firstcomponent to determine that speech is represented in a portion of thesecond audio data; perform the first action; process the second audiodata using the second component to determine a confidence valueindicating a likelihood that the second audio data corresponds to adevice-directed speech event; determine that the confidence valuesatisfies a condition; and perform a second action.
 18. The system ofclaim 16, wherein the memory further comprises instructions that, whenexecuted by the at least one processor, further cause the system to:generate second output audio using the loudspeaker; receive second audiodata; process the second audio data using the first component todetermine that a first portion of the second audio data representssecond speech that is directed to the device; perform the first action;determine that the second speech is represented in a second portion ofthe second audio data that includes the first portion of the secondaudio data; process the second portion of the second audio data usingthe second component to determine that the second speech is not directedto the device; and perform a second action.
 19. The system of claim 16,wherein the memory further comprises instructions that, when executed bythe at least one processor, further cause the system to: detect, by aspeech processing component of the device, an endpoint of the firstspeech represented in the first audio data; determine, by the speechprocessing component, semantic information associated with the firstspeech; and process, using a classifier of the second component, thesecond portion of the first audio data and the semantic information todetermine that the first speech corresponds to a device-directed speechevent.
 20. The system of claim 16, wherein the memory further comprisesinstructions that, when executed by the at least one processor, furthercause the system to: determine a current position in output audio data,the output audio data corresponding to the first output audio; identifya word boundary represented in the output audio data after the currentposition; determine a first portion of the output audio data ending atthe word boundary; generate the first output audio using the loudspeakerand the first portion of the output audio data; and cause the firstoutput audio to be stopped after the first portion of the output audiodata.